[Tux4kids-commits] r1032 - in tuxmath/branches/lan: . server src

akash gangil gangil-guest at alioth.debian.org
Thu Jun 11 21:13:32 UTC 2009


Author: gangil-guest
Date: 2009-06-11 21:13:31 +0000 (Thu, 11 Jun 2009)
New Revision: 1032

Added:
   tuxmath/branches/lan/server/
   tuxmath/branches/lan/server/mathcards.c
   tuxmath/branches/lan/server/mathcards.h
   tuxmath/branches/lan/server/server.c
Modified:
   tuxmath/branches/lan/src/mathcards.c
Log:
Adding server dir

Added: tuxmath/branches/lan/server/mathcards.c
===================================================================
--- tuxmath/branches/lan/server/mathcards.c	                        (rev 0)
+++ tuxmath/branches/lan/server/mathcards.c	2009-06-11 21:13:31 UTC (rev 1032)
@@ -0,0 +1,2459 @@
+/*
+*  C Implementation: mathcards.c
+*
+*       Description: implementation of backend for a flashcard-type math game.
+        Developed as an enhancement to Bill Kendrick's "Tux of Math Command"
+        (aka tuxmath).  (If tuxmath were a C++ program, this would be a C++ class).
+        MathCards could be used as the basis for similar games using a different interface.
+
+*
+*
+* Author: David Bruce <dbruce at tampabay.rr.com>, (C) 2005
+*
+* Copyright: See COPYING file that comes with this distribution.  (Briefly, GNU GPL).
+*
+* Revised extensively in 2008 by Brendan Luchen, Tim Holy, and David Bruce
+*
+*/
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <math.h>
+#include <time.h>
+
+#include "mathcards.h"
+
+
+/* extern'd constants */
+
+const char* const MC_OPTION_TEXT[NOPTS+1] = {
+"PLAY_THROUGH_LIST",
+"QUESTION_COPIES",
+"REPEAT_WRONGS",
+"COPIES_REPEATED_WRONGS",
+"ALLOW_NEGATIVES",
+"MAX_ANSWER",
+"MAX_QUESTIONS",
+"MAX_FORMULA_NUMS",
+"MIN_FORMULA_NUMS",
+
+"FORMAT_ANSWER_LAST",
+"FORMAT_ANSWER_FIRST",
+"FORMAT_ANSWER_MIDDLE",
+"FORMAT_ADD_ANSWER_LAST",
+"FORMAT_ADD_ANSWER_FIRST",
+"FORMAT_ADD_ANSWER_MIDDLE",
+"FORMAT_SUB_ANSWER_LAST",
+"FORMAT_SUB_ANSWER_FIRST",
+"FORMAT_SUB_ANSWER_MIDDLE",
+"FORMAT_MULT_ANSWER_LAST",
+"FORMAT_MULT_ANSWER_FIRST",
+"FORMAT_MULT_ANSWER_MIDDLE",
+"FORMAT_DIV_ANSWER_LAST",
+"FORMAT_DIV_ANSWER_FIRST",
+"FORMAT_DIV_ANSWER_MIDDLE",
+
+"ADDITION_ALLOWED",
+"SUBTRACTION_ALLOWED",
+"MULTIPLICATION_ALLOWED",
+"DIVISION_ALLOWED",
+"TYPING_PRACTICE_ALLOWED",
+"ARITHMETIC_ALLOWED",
+"COMPARISON_ALLOWED",
+
+"MIN_AUGEND",
+"MAX_AUGEND",
+"MIN_ADDEND",
+"MAX_ADDEND",
+
+"MIN_MINUEND",
+"MAX_MINUEND",
+"MIN_SUBTRAHEND",
+"MAX_SUBTRAHEND",
+
+"MIN_MULTIPLIER",
+"MAX_MULTIPLIER",
+"MIN_MULTIPLICAND",
+"MAX_MULTIPLICAND",
+
+"MIN_DIVISOR",
+"MAX_DIVISOR",
+"MIN_QUOTIENT",
+"MAX_QUOTIENT",
+
+"MIN_TYPING_NUM",
+"MAX_TYPING_NUM",
+
+"MIN_COMPARATOR" ,
+"MAX_COMPARATOR" ,
+"MIN_COMPARISAND",
+"MAX_COMPARISAND",
+
+"RANDOMIZE",
+
+"COMPREHENSIVE",
+"AVG_LIST_LENGTH",
+"VARY_LIST_LENGTH",
+
+"END_OF_OPTS"
+};
+
+
+  
+const int MC_DEFAULTS[] = {
+  1,    //PLAY_THROUGH_LIST
+  1,    //QUESTION_COPIES
+  1,    //REPEAT_WRONGS
+  1,    //COPIES_REPEATED_WRONGS
+  0,    //ALLOW_NEGATIVES
+  999,  //MAX_ANSWER
+  5000, //MAX_QUESTIONS
+  2,    //MAX_FORMULA_NUMS
+  2,    //MIN_FORMULA_NUMS
+        //
+  1,    //FORMAT_ANSWER_LAST
+  0,    //FORMAT_ANSWER_FIRST
+  0,    //FORMAT_ANSWER_MIDDLE
+  1,    //FORMAT_ADD_ANSWER_LAST
+  0,    //FORMAT_ADD_ANSWER_FIRST
+  0,    //FORMAT_ADD_ANSWER_MIDDLE
+  1,    //FORMAT_SUB_ANSWER_LAST
+  0,    //FORMAT_SUB_ANSWER_FIRST
+  0,    //FORMAT_SUB_ANSWER_MIDDLE
+  1,    //FORMAT_MULT_ANSWER_LAST
+  0,    //FORMAT_MULT_ANSWER_FIRST
+  0,    //FORMAT_MULT_ANSWER_MIDDLE
+  1,    //FORMAT_DIV_ANSWER_LAST
+  0,    //FORMAT_DIV_ANSWER_FIRST
+  0,    //FORMAT_DIV_ANSWER_MIDDLE
+        //
+  1,    //ADDITION_ALLOWED
+  1,    //SUBTRACTION_ALLOWED
+  1,    //MULTIPLICATION_ALLOWED
+  1,    //DIVISION_ALLOWED
+
+  0,    //TYPING_PRACTICE_ALLOWED
+  1,    //ARITHMETIC_ALLOWED
+  0,    //COMPARISON_ALLOWED
+        //
+  0,    //MIN_AUGEND
+  12,   //MAX_AUGEND
+  0,    //MIN_ADDEND
+  12,   //MAX_ADDEND
+        //
+  0,    //MIN_MINUEND
+  12,   //MAX_MINUEND
+  0,    //MIN_SUBTRAHEND
+  12,   //MAX_SUBTRAHEND
+        //
+  0,    //MIN_MULTIPLIER
+  12,   //MAX_MULTIPLIER
+  0,    //MIN_MULTIPLICAND
+  12,   //MAX_MULTIPLICAND
+        //
+  0,    //MIN_DIVISOR
+  12,   //MAX_DIVISOR
+  0,    //MIN_QUOTIENT
+  12,   //MAX_QUOTIENT
+        //
+  0,    //MIN_TYPING_NUM
+  12,   //MAX_TYPING_NUM
+        //
+  0,    //MIN_COMPARATOR
+  12,   //MAX_COMPARATOR
+  0,    //MIN_COMPARISAND
+  12,   //MAX_COMPARISAND
+
+  1,    //RANDOMIZE
+
+  0,    //COMPREHENSIVE
+  100,  //AVG_LIST_LENGTH
+  1     //VARY_LIST_LENGTH
+};
+
+
+
+/* "Globals" for mathcards.c: */
+#define PI_VAL 3.1415927
+#define NPRIMES 9
+const int smallprimes[NPRIMES] = {2, 3, 5 ,7, 11, 13, 17, 19, 23};
+const char operchars[4] = "+-*/";
+extern int n;
+
+MC_Options* math_opts = 0;
+MC_MathQuestion* question_list = 0;
+MC_MathQuestion* wrong_quests = 0;
+MC_MathQuestion* next_wrong_quest = 0;
+int initialized = 0;
+int quest_list_length = 0;
+int answered_correctly = 0;
+int answered_wrong = 0;
+int questions_pending = 0;
+int unanswered = 0;
+int starting_length = 0;
+int max_formula_size = 0; //max length in chars of a flashcard's formula
+int max_answer_size = 0; //and of its answer
+
+/* For keeping track of timing data */
+float* time_per_question_list = NULL;
+int length_time_per_question_list = 0;
+int length_alloc_time_per_question_list = 0;
+
+const MC_FlashCard DEFAULT_CARD = {NULL,NULL,0,0}; //empty card to signal error
+
+/* "private" function prototypes:                        */
+/*                                                       */
+/* these are for internal use by MathCards only - like   */
+/* the private functions of a C++ class. Declared static */
+/* to give file scope rather than extern scope.          */
+
+static MC_MathQuestion* generate_list(void);
+static void clear_negatives(void);
+//static int validate_question(int n1, int n2, int n3);
+//static MC_MathQuestion* create_node(int n1, int n2, int op, int ans, int f);
+static MC_MathQuestion* create_node_from_card(const MC_FlashCard* flashcard);
+static MC_MathQuestion* insert_node(MC_MathQuestion* first, MC_MathQuestion* current, MC_MathQuestion* new_node);
+static MC_MathQuestion* append_node(MC_MathQuestion* list, MC_MathQuestion* new_node);
+static MC_MathQuestion* remove_node(MC_MathQuestion* first, MC_MathQuestion* n);
+static MC_MathQuestion* delete_list(MC_MathQuestion* list);
+//static int copy_node(MC_MathQuestion* original, MC_MathQuestion* copy);
+static int list_length(MC_MathQuestion* list);
+static int randomize_list(MC_MathQuestion** list);
+
+int comp_randomizer(const void *a, const void *b);
+static MC_MathQuestion* pick_random(int length, MC_MathQuestion* list);
+static int compare_node(MC_MathQuestion* first, MC_MathQuestion* other);
+static int already_in_list(MC_MathQuestion* list, MC_MathQuestion* ptr);
+//static int int_to_bool(int i);
+//static int sane_value(int i);
+//static int abs_value(int i);
+static int log10i(int i);
+static int floatCompare(const void *v1,const void *v2);
+
+static void print_list(FILE* fp,MC_MathQuestion* list);
+void print_vect_list(FILE* fp, MC_MathQuestion** vect, int length);
+
+/* these functions are dead code unless compiling with debug turned on: */
+#ifdef MC_DEBUG
+static void print_card(MC_FlashCard card);
+static void print_counters(void);
+//static MC_MathQuestion* create_node_copy(MC_MathQuestion* other);
+//static MC_FlashCard    create_card_from_node(MC_MathQuestion* node);
+#endif
+
+/* Functions for new mathcards architecture */
+static void free_node(MC_MathQuestion* mq); //wrapper for free() that also frees card
+static MC_FlashCard generate_random_flashcard(void);
+static MC_FlashCard generate_random_ooo_card_of_length(int length, int reformat);
+static void copy_card(const MC_FlashCard* src, MC_FlashCard* dest); //deep copy a flashcard
+static MC_MathQuestion* allocate_node(void); //allocate space for a node
+static int compare_card(const MC_FlashCard* a, const MC_FlashCard* b); //test for identical cards
+static int find_divisor(int a); //return a random positive divisor of a
+static int calc_num_valid_questions(void);
+static MC_MathQuestion* add_all_valid(MC_ProblemType pt, MC_MathQuestion* list, MC_MathQuestion** end_of_list);
+static MC_MathQuestion* find_node(MC_MathQuestion* list, int num);
+
+/*  MC_Initialize() sets up the struct containing all of  */
+/*  settings regarding math questions.  It should be      */
+/*  called before any other function.  Many of the other  */
+/*  functions will not work properly if MC_Initialize()   */
+/*  has not been called. It only needs to be called once, */
+/*  i.e when the program is starting, not at the beginning*/
+/*  of each math game for the player. Returns 1 if        */
+/*  successful, 0 otherwise.                              */
+int MC_Initialize(void)
+{
+  int i;
+
+  mcdprintf("\nEntering MC_Initialize()");
+  /* check flag to see if we did this already */
+  if (initialized)
+  {
+
+    #ifdef MC_DEBUG
+    printf("\nAlready initialized");
+    MC_PrintMathOptions(stdout, 0);
+    printf("\nLeaving MC_Initialize()\n");
+    #endif
+
+    return 1;
+  }
+  math_opts = malloc(sizeof(MC_Options));
+  /* bail out if no struct */
+  if (!math_opts)
+  {
+
+    mcdprintf("\nError: math_opts null or invalid");
+    mcdprintf("\nLeaving MC_Initialize()\n");
+
+    fprintf(stderr, "\nUnable to initialize math_options");
+    return 0;
+  }
+
+  /* set defaults */
+  for (i = 0; i < NOPTS; ++i)
+    {
+    math_opts->iopts[i] = MC_DEFAULTS[i];
+    }
+
+  /* if no negatives to be used, reset any negatives to 0 */
+  if (!math_opts->iopts[ALLOW_NEGATIVES])
+  {
+    clear_negatives();
+  }
+
+  initialized = 1;
+
+  #ifdef MC_DEBUG
+  MC_PrintMathOptions(stdout, 0);
+  printf("\nLeaving MC_Initialize()\n");
+  #endif
+
+  return 1;
+}
+
+
+
+/*  MC_StartGame() generates the list of math questions   */
+/*  based on existing settings. It should be called at    */
+/*  the beginning of each math game for the player.       */
+/*  Returns 1 if resultant list contains 1 or more        */
+/*  questions, 0 if list empty or not generated           */
+/*  successfully.                                         */
+int MC_StartGame(void)
+{
+
+  mcdprintf("\nEntering MC_StartGame()");
+
+  /* if math_opts not set up yet, initialize it: */
+  if (!initialized)
+  {
+
+    mcdprintf("\nNot initialized - calling MC_Initialize()");
+
+    MC_Initialize();
+  }
+
+  if (!math_opts)
+  {
+    mcdprintf("\nCould not initialize - bailing out");
+    mcdprintf("\nLeaving MC_StartGame()\n");
+
+    return 0;
+  }
+  /* we know math_opts exists if we make it to here */
+  srand(time(NULL));
+
+  /* clear out old lists if starting another game: (if not done already) */
+  delete_list(question_list);
+  question_list = NULL;
+  delete_list(wrong_quests);
+  wrong_quests = NULL;
+
+  /* clear the time list */
+  if (time_per_question_list != NULL) {
+    free(time_per_question_list);
+    time_per_question_list = NULL;
+    length_time_per_question_list = 0;
+    length_alloc_time_per_question_list = 0;
+  }
+
+  /* determine how much space needed for strings, based on user options */
+  max_formula_size = MC_GetOpt(MAX_FORMULA_NUMS)
+                   * (log10i(MC_GLOBAL_MAX) + 4) //sign/operator/spaces
+                   + 1; //question mark for answer
+  max_answer_size = (int)(log10i(MC_GLOBAL_MAX) ) + 2; //negative sign + digit
+
+  mcdprintf("max answer, formula size: %d, %d\n",
+            max_answer_size, max_formula_size);
+  /* set up new list with pointer to top: */
+// if(n==1)                             				//if selects server , n==1 from titlescreen.c 
+//  { 
+   question_list = generate_list();
+
+   next_wrong_quest = 0;
+   /* initialize counters for new game: */
+   quest_list_length = list_length(question_list);
+  
+//   SendQuestionList(question_list,quest_list_length);
+//  } 
+  
+//if(n==0)							//if selects client , n==0 from titlescreen.c
+//{
+//   next_wrong_quest = 0;
+//   ReceiveQuestionList(question_list,quest_list_length);
+ 
+//}
+  /* Note: the distinction between quest_list_length and  */
+  /* unanswered is that the latter includes questions     */
+  /* that are currently "in play" by the user interface - */
+  /* it is only decremented when an answer to the question*/
+  /* is received.                                         */
+  unanswered = starting_length = quest_list_length;
+  answered_correctly = 0;
+  answered_wrong = 0;
+  questions_pending = 0;
+
+  #ifdef MC_DEBUG
+  print_counters();
+  #endif
+
+  /* make sure list now exists and has non-zero length: */
+  if (question_list && quest_list_length)
+  {
+    mcdprintf("\nGame set up successfully");
+    mcdprintf("\nLeaving MC_StartGame()\n");
+
+    return 1;
+  }
+  else
+  {
+    mcdprintf("\nGame NOT set up successfully - no valid list");
+    mcdprintf("\nLeaving MC_StartGame()\n");
+
+    return 0;
+  }
+}
+
+/*  MC_StartGameUsingWrongs() is like MC_StartGame(),     */
+/*  but uses the incorrectly answered questions from the  */
+/*  previous game for the question list as a review form  */
+/*  of learning. If there were no wrong answers (or no    */
+/*  previous game), it behaves just like MC_StartGame().  */
+/*  FIXME wonder if it should return a different value if */
+/*  the list is created from settings because there is no */
+/*  valid wrong question list?                            */
+int MC_StartGameUsingWrongs(void)
+{
+  mcdprintf("\nEntering MC_StartGameUsingWrongs()");
+
+  /* Note: if not initialized, control will pass to       */
+  /* MC_StartGame() via else clause so don't need to test */
+  /* for initialization here                              */
+  if (wrong_quests &&
+      list_length(wrong_quests))
+  {
+    mcdprintf("\nNon-zero length wrong_quests list found, will");
+    mcdprintf("\nuse for new game list:");
+
+    /* initialize lists for new game: */
+    delete_list(question_list);
+    if(!randomize_list(&wrong_quests)) {
+      fprintf(stderr, "Error during randomization of wrong_quests!\n");
+      /* Punt on trying wrong question list, just run normal game */
+      return MC_StartGame();
+    }
+    question_list = wrong_quests;
+    wrong_quests = 0;
+    next_wrong_quest = 0;
+   /* initialize counters for new game: */
+    quest_list_length = list_length(question_list);
+    unanswered = starting_length = quest_list_length;
+    answered_correctly = 0;
+    answered_wrong = 0;
+    questions_pending = 0;
+
+    #ifdef MC_DEBUG
+    print_counters();
+    print_list(stdout, question_list);
+    printf("\nLeaving MC_StartGameUsingWrongs()\n");
+    #endif
+
+    return 1;
+  }
+  else /* if no wrong_quests list, go to MC_StartGame()   */
+       /* to set up list based on math_opts               */
+  {
+    mcdprintf("\nNo wrong questions to review - generate list from math_opts\n");
+    mcdprintf("\nLeaving MC_StartGameUsingWrongs()\n");
+
+    return MC_StartGame();
+  }
+}
+
+
+/*  MC_NextQuestion() takes a pointer to an allocated     */
+/*  MC_MathQuestion struct and fills in the fields for    */
+/*  use by the user interface program. It basically is    */
+/*  like taking the next flashcard from the pile. The     */
+/*  node containing the question is removed from the list.*/
+/*  Returns 1 if question found, 0 if list empty/invalid  */
+/*  or if argument pointer is invalid.                    */
+int MC_NextQuestion(MC_FlashCard* fc)
+{
+  mcdprintf("\nEntering MC_NextQuestion()\n");
+
+  /* (so we can free the node after removed from list:) */
+  MC_MathQuestion* ptr;
+  ptr = question_list;
+
+  if (!fc )
+  {
+    fprintf(stderr, "\nNull MC_FlashCard* argument!\n");
+    mcdprintf("\nLeaving MC_NextQuestion()\n");
+    return 0;
+  }
+
+  if (!question_list ||
+/*      !next_question || */
+      !list_length(question_list) )
+  {
+    mcdprintf("\nquestion_list invalid or empty");
+    mcdprintf("\nLeaving MC_NextQuestion()\n");
+
+    return 0;
+  }
+
+  /* 'draw' - copy over the first question */
+  copy_card(&question_list->card, fc);
+ 
+  /* 'discard' - take first question node out of list and free it */
+  question_list = remove_node(question_list, question_list);
+  free_node(ptr);
+  quest_list_length--;
+  questions_pending++;
+
+  #ifdef MC_DEBUG
+  printf("\nnext question is:");
+  print_card(*fc);
+  print_counters();
+  printf("\n\nLeaving MC_NextQuestion()\n");
+  #endif
+
+  return 1;
+}
+
+/*  MC_AnsweredCorrectly() is how the user interface      */
+/*  tells MathCards that the question has been answered   */
+/*  correctly. Returns 1 if no errors.                    */
+int MC_AnsweredCorrectly(MC_FlashCard* fc)
+{
+  mcdprintf("\nEntering MC_AnsweredCorrectly()");
+
+  if (!fc)
+  {
+    fprintf(stderr, "\nMC_AnsweredCorrectly() passed invalid pointer as argument!\n");
+
+    mcdprintf("\nInvalid MC_FlashCard* argument!");
+    mcdprintf("\nLeaving MC_AnsweredCorrectly()\n");
+
+    return 0;
+  }
+
+  #ifdef MC_DEBUG
+  printf("\nQuestion was:");
+  print_card(*fc);
+  #endif
+
+  answered_correctly++;
+  questions_pending--;
+
+  if (!math_opts->iopts[PLAY_THROUGH_LIST])
+  /* reinsert question into question list at random location */
+  {
+    mcdprintf("\nReinserting question into list");
+
+    MC_MathQuestion* ptr1;
+    MC_MathQuestion* ptr2;
+    /* make new node using values from flashcard */
+    ptr1 = create_node_from_card(fc);
+    /* put it into list */
+    ptr2 = pick_random(quest_list_length, question_list);
+    question_list = insert_node(question_list, ptr2, ptr1);
+    quest_list_length++;
+    /* unanswered does not change - was not decremented when */
+    /* question allocated!                                   */
+  }
+  else
+  {
+    mcdprintf("\nNot reinserting question into list");
+    /* not recycling questions so fewer questions remain:      */
+    unanswered--;
+  }
+
+  #ifdef MC_DEBUG
+  print_counters();
+  printf("\nLeaving MC_AnsweredCorrectly()\n");
+  #endif
+
+  return 1;
+}
+
+/*  MC_NotAnsweredCorrectly() is how the user interface    */
+/*  tells MathCards that the player failed to answer the  */
+/*  question correctly. Returns 1 if no errors.           */
+/*  Note: this gets triggered only if a player's city     */
+/*  gets hit by a question, not if they "miss".           */
+int MC_NotAnsweredCorrectly(MC_FlashCard* fc)
+{
+  mcdprintf("\nEntering MC_NotAnsweredCorrectly()");
+
+  if (!fc)
+  {
+    fprintf(stderr, "\nMC_NotAnsweredCorrectly() passed invalid pointer as argument!\n");
+
+    mcdprintf("\nInvalid MC_FlashCard* argument!");
+    mcdprintf("\nLeaving MC_NotAnsweredCorrectly()\n");
+
+    return 0;
+  }
+
+  #ifdef MC_DEBUG
+  printf("\nQuestion was:");
+  print_card(*fc);
+  #endif
+
+  answered_wrong++;
+  questions_pending--;
+
+  /* add question to wrong_quests list: */
+
+  MC_MathQuestion* ptr1;
+  MC_MathQuestion* ptr2;
+
+  ptr1 = create_node_from_card(fc);
+
+  if (!already_in_list(wrong_quests, ptr1)) /* avoid duplicates */
+  {
+    mcdprintf("\nAdding to wrong_quests list");
+    wrong_quests = append_node(wrong_quests, ptr1);
+  }
+  else /* avoid memory leak */
+  {
+    free(ptr1);
+  }
+
+  /* if desired, put question back in list so student sees it again */
+  if (math_opts->iopts[REPEAT_WRONGS])
+  {
+    int i;
+
+    mcdprintf("\nAdding %d copies to question_list:", math_opts->iopts[COPIES_REPEATED_WRONGS]);
+
+    /* can put in more than one copy (to drive the point home!) */
+    for (i = 0; i < math_opts->iopts[COPIES_REPEATED_WRONGS]; i++)
+    {
+      ptr1 = create_node_from_card(fc);
+      ptr2 = pick_random(quest_list_length, question_list);
+      question_list = insert_node(question_list, ptr2, ptr1);
+      quest_list_length++;
+    }
+    /* unanswered stays the same if a single copy recycled or */
+    /* increases by 1 for each "extra" copy reinserted:       */
+    unanswered += (math_opts->iopts[COPIES_REPEATED_WRONGS] - 1);
+  }
+  else
+  {
+    mcdprintf("\nNot repeating wrong answers\n");
+
+    /* not repeating questions so list gets shorter:      */
+    unanswered--;
+  }
+
+  #ifdef MC_DEBUG
+  print_counters();
+  printf("\nLeaving MC_NotAnswered_Correctly()\n");
+  #endif
+
+  return 1;
+
+}
+
+/* Tells user interface if all questions have been answered correctly! */
+/* Requires that at list contained at least one question to start with */
+/* and that wrongly answered questions have been recycled.             */
+int MC_MissionAccomplished(void)
+{
+  if (starting_length
+    && math_opts->iopts[REPEAT_WRONGS]
+    && !unanswered)
+  {
+    return 1;
+  }
+  else
+  {
+    return 0;
+  }
+}
+
+/*  Returns number of questions left (either in list       */
+/*  or "in play")                                          */
+int MC_TotalQuestionsLeft(void)
+{
+  return unanswered;
+}
+
+/*  Returns number of questions left in list, NOT       */
+/*  including questions currently "in play".            */
+int MC_ListQuestionsLeft(void)
+{
+  return quest_list_length;
+}
+
+
+/*  Store the amount of time a given flashcard was      */
+/*  visible on the screen. Returns 1 if the request     */
+/*  succeeds, 0 otherwise.                              */
+int MC_AddTimeToList(float t)
+{
+  int newsize = 0;
+  float *newlist;
+
+  /* This list will be allocated in an STL-like manner: when the       */
+  /* list gets full, allocate an additional amount of storage equal    */
+  /* to the current size of the list, so that only O(logN) allocations */
+  /* will ever be needed. We therefore have to keep track of 2 sizes:  */
+  /* the allocated size, and the actual number of items currently on   */
+  /* the list.                                                         */
+  if (length_time_per_question_list >= length_alloc_time_per_question_list) {
+    /* The list is full, allocate more space */
+    newsize = 2*length_time_per_question_list;
+    if (newsize == 0)
+      newsize = 100;
+    newlist = realloc(time_per_question_list, newsize*sizeof(float));
+    if (newlist == NULL) {
+      #ifdef MC_DEBUG
+      printf("\nError: allocation for time_per_question_list failed\n");
+      #endif
+      return 0;
+    }
+    time_per_question_list = newlist;
+    length_alloc_time_per_question_list = newsize;
+  }
+
+  /* Append the time to the list */
+  time_per_question_list[length_time_per_question_list++] = t;
+  return 1;
+}
+
+/* Frees heap memory used in program:                   */
+void MC_EndGame(void)
+{
+  delete_list(question_list);
+  question_list = 0;
+  delete_list(wrong_quests);
+  wrong_quests = 0;
+
+  if (math_opts)
+  {
+    free(math_opts);
+    math_opts = 0;
+  }
+
+  free(time_per_question_list);
+  time_per_question_list = NULL;
+  length_alloc_time_per_question_list = 0;
+  length_time_per_question_list = 0;
+
+  initialized = 0;
+}
+
+
+
+/* prints struct to file */
+void MC_PrintMathOptions(FILE* fp, int verbose)
+{
+  int i, vcommentsprimed = 0;
+  //comments when writing out verbose...perhaps they can go somewhere less conspicuous
+  static char* vcomments[NOPTS];
+  if (!vcommentsprimed) //we only want to initialize these once
+  {
+    vcommentsprimed = 1;
+    for (i = 0; i < NOPTS; ++i)
+      vcomments[i] = NULL;
+    vcomments[PLAY_THROUGH_LIST] =
+      "\n############################################################\n"
+      "#                                                          #\n"
+      "#                  General Math Options                    #\n"
+      "#                                                          #\n"
+      "# If 'play_through_list' is true, Tuxmath will ask each    #\n"
+      "# question in an internally-generated list. The list is    #\n"
+      "# generated based on the question ranges selected below.   #\n"
+      "# The game ends when no questions remain.                  #\n"
+      "# If 'play_through_list' is false, the game continues      #\n"
+      "# until all cities are destroyed.                          #\n"
+      "# Default is 1 (i.e. 'true' or 'yes').                     #\n"
+      "#                                                          #\n"
+      "# 'question_copies' is the number of times each question   #\n"
+      "# will be asked. It can be 1 to 10 - Default is 1.         #\n"
+      "#                                                          #\n"
+      "# 'repeat_wrongs' tells Tuxmath whether to reinsert        #\n"
+      "# incorrectly answered questions into the list to be       #\n"
+      "# asked again. Default is 1 (yes).                         #\n"
+      "#                                                          #\n"
+      "# 'copies_repeated_wrongs' gives the number of times an    #\n"
+      "# incorrectly answered question will reappear. Default     #\n"
+      "# is 1.                                                    #\n"
+      "#                                                          #\n"
+      "# The defaults for these values result in a 'mission'      #\n"
+      "# for Tux that is accomplished by answering all            #\n"
+      "# questions correctly with at least one surviving city.    #\n"
+      "############################################################\n\n";
+
+    vcomments[FORMAT_ADD_ANSWER_LAST] =
+      "\n############################################################\n"
+      "# The 'format_<op>_answer_<place>  options control         #\n"
+      "# generation of questions with the answer in different     #\n"
+      "# places in the equation.  i.e.:                           #\n"
+      "#                                                          #\n"
+      "#    format_add_answer_last:    2 + 2 = ?                  #\n"
+      "#    format_add_answer_first:   ? + 2 = 4                  #\n"
+      "#    format_add_answer_middle:  2 + ? = 4                  #\n"
+      "#                                                          #\n"
+      "# By default, 'format_answer_first' is enabled and the     #\n"
+      "# other two formats are disabled.  Note that the options   #\n"
+      "# are not mutually exclusive - the question list may       #\n"
+      "# contain questions with different formats.                #\n"
+      "#                                                          #\n"
+      "# The formats are set independently for each of the four   #\n"
+      "# math operations.                                         #\n"
+      "############################################################\n\n";
+
+    vcomments[ALLOW_NEGATIVES] =
+      "\n############################################################\n"
+      "# 'allow_negatives' allows or disallows use of negative    #\n"
+      "# numbers as both operands and answers.  Default is 0      #\n"
+      "# (no), which disallows questions like:                    #\n"
+      "#          2 - 4 = ?                                       #\n"
+      "# Note: this option must be enabled in order to set the    #\n"
+      "# operand ranges to include negatives (see below). If it   #\n"
+      "# is changed from 1 (yes) to 0 (no), any negative          #\n"
+      "# operand limits will be reset to 0.                       #\n"
+      "############################################################\n\n";
+
+    vcomments[MAX_ANSWER] =
+      "\n############################################################\n"
+      "# 'max_answer' is the largest absolute value allowed in    #\n"
+      "# any value in a question (not only the answer). Default   #\n"
+      "# is 144. It can be set as high as 999.                    #\n"
+      "############################################################\n\n";
+
+    vcomments[MAX_QUESTIONS] =
+      "\n############################################################\n"
+      "# 'max_questions' is limit of the length of the question   #\n"
+      "# list. Default is 5000 - only severe taskmasters will     #\n"
+      "# need to raise it.                                        #\n"
+      "############################################################\n\n";
+
+    vcomments[RANDOMIZE] =
+      "\n############################################################\n"
+      "# If 'randomize' selected, the list will be shuffled       #\n"
+      "# at the start of the game.  Default is 1 (yes).           #\n"
+      "############################################################\n\n";
+
+    vcomments[ADDITION_ALLOWED] =
+      "\n############################################################\n"
+      "#                                                          #\n"
+      "#                 Math Operations Allowed                  #\n"
+      "#                                                          #\n"
+      "# These options enable questions for each of the four math #\n"
+      "# operations.  All are 1 (yes) by default.                 #\n"
+      "############################################################\n\n";
+
+    vcomments[MIN_AUGEND] =
+      "\n############################################################\n"
+      "#                                                          #\n"
+      "#      Minimum and Maximum Values for Operand Ranges       #\n"
+      "#                                                          #\n"
+      "# Operand limits can be set to any integer up to the       #\n"
+      "# value of 'max_answer'.  If 'allow_negatives' is set to 1 #\n"
+      "# (yes), either negative or positive values can be used.   #\n"
+      "# Tuxmath will generate questions for every value in the   #\n"
+      "# specified range. The maximum must be greater than or     #\n"
+      "# equal to the corresponding minimum for any questions to  #\n"
+      "# be generated for that operation.                         #\n"
+      "############################################################\n\n";
+
+  }
+
+
+  mcdprintf("\nEntering MC_PrintMathOptions()\n");
+
+  /* bail out if no struct */
+  if (!math_opts)
+  {
+    fprintf(stderr, "\nMath Options struct does not exist!\n");
+    return;
+  }
+
+  for (i = 0; i < NOPTS; ++i)
+    {
+    if (verbose && vcomments[i] != NULL)
+      fprintf(fp, "%s", vcomments[i]);
+    fprintf(fp, "%s = %d\n", MC_OPTION_TEXT[i], math_opts->iopts[i]);
+    }
+  mcdprintf("\nLeaving MC_PrintMathOptions()\n");
+}
+
+
+
+int MC_PrintQuestionList(FILE* fp)
+{
+  if (fp && question_list)
+  {
+    print_list(fp, question_list);
+    return 1;
+  }
+  else
+  {
+    fprintf(stderr, "\nFile pointer and/or question list invalid\n");
+    return 0;
+  }
+}
+
+int MC_PrintWrongList(FILE* fp)
+{
+  if (!fp)
+  {
+    fprintf(stderr, "File pointer invalid\n");
+    return 0;
+  }
+
+  if (wrong_quests)
+  {
+    print_list(fp, wrong_quests);
+  }
+  else
+  {
+    fprintf(fp, "\nNo wrong questions!\n");
+  }
+
+  return 1;
+}
+
+
+int MC_StartingListLength(void)
+{
+  return starting_length;
+}
+
+
+int MC_WrongListLength(void)
+{
+  return list_length(wrong_quests);
+}
+
+int MC_NumAnsweredCorrectly(void)
+{
+  return answered_correctly;
+}
+
+
+int MC_NumNotAnsweredCorrectly(void)
+{
+  return answered_wrong;
+}
+
+
+/* Report the median time per question */
+float MC_MedianTimePerQuestion(void)
+{
+  if (length_time_per_question_list == 0)
+    return 0;
+
+  qsort(time_per_question_list,length_time_per_question_list,sizeof(float),floatCompare);
+  return time_per_question_list[length_time_per_question_list/2];
+}
+
+/* Implementation of "private methods" - (cannot be called from outside
+of this file) */
+
+
+
+/* Resets negative values to zero - used when allow_negatives deselected. */
+void clear_negatives(void)
+{
+  int i;
+  for (i = MIN_AUGEND; i <= MAX_TYPING_NUM; ++i)
+    if (math_opts->iopts[i]< 0)
+      math_opts->iopts[i]= 0;
+}
+
+// /* this is used by generate_list to see if a possible question */
+// /* meets criteria to be added to the list or not:              */
+// int validate_question(int n1, int n2, int n3)
+// {
+//   /* make sure none of values exceeds max_answer using absolute */
+//   /* value comparison:                                          */
+//   if (abs_value(n1) > abs_value(math_opts->iopts[MAX_ANSWER])
+//    || abs_value(n2) > abs_value(math_opts->iopts[MAX_ANSWER])
+//    || abs_value(n3) > abs_value(math_opts->iopts[MAX_ANSWER]))
+//   {
+//     return 0;
+//   }
+//   /* make sure none of values are negative if negatives not allowed: */
+//   if (!math_opts->iopts[ALLOW_NEGATIVES])
+//   {
+//     if (n1 < 0 || n2 < 0 || n3 < 0)
+//     {
+//       return 0;
+//     }
+//   }
+//   return 1;
+// }
+
+#if 0 //this code is probably on the way out...
+/* create a new node and return a pointer to it */
+MC_MathQuestion* create_node(int n1, int n2, int op, int ans, int f)
+{
+  MC_MathQuestion* ptr = NULL;
+
+  ptr = (MC_MathQuestion*)malloc(sizeof(MC_MathQuestion));
+
+  if (!ptr)
+  {
+    fprintf(stderr, "create_node() - malloc() failed!\n");
+    return NULL;
+  }
+
+  ptr->card = MC_AllocateFlashcard();
+  ptr->next = NULL;
+  ptr->previous = NULL;
+
+  snprintf(ptr->card.formula_string, max_formula_size, "%d %c %d = ?",
+           n1, op < MC_NUM_OPERS ? operchars[op] : '\0', n2);
+  snprintf(ptr->card.answer_string, max_formula_size, "%d", ans);
+  ptr->card.difficulty = 25 * (op + 1);
+
+
+  /* ptr should now point to a properly constructed node: */
+  return ptr;
+}
+#endif
+
+MC_MathQuestion* create_node_from_card(const MC_FlashCard* flashcard)
+{
+  MC_MathQuestion* ret = allocate_node();
+  copy_card(flashcard, &(ret->card));
+  return ret;
+}
+
+// /* FIXME take care of strings */
+// /* this one copies the contents, including pointers; both nodes must be allocated */
+// int copy_node(MC_MathQuestion* original, MC_MathQuestion* copy)
+// {
+//   if (!original)
+//   {
+//     fprintf(stderr, "\nIn copy_node(): invalid 'original' pointer arg.\n");
+//     return 0;
+//   }
+//   if (!copy)
+//   {
+//     fprintf(stderr, "\nIn copy_node(): invalid 'copy' pointer arg.\n");
+//     return 0;
+//   }
+// 
+//   copy_card(&(original->card), &(copy->card) );
+// 
+//   copy->next = original->next;
+//   copy->previous = original->previous;
+//   copy->randomizer = original->randomizer;
+//   return 1;
+// }
+
+
+
+
+/* this puts the node into the list AFTER the node pointed to by current */
+/* and returns a pointer to the top of the modified list  */
+MC_MathQuestion* insert_node(MC_MathQuestion* first, MC_MathQuestion* current, MC_MathQuestion* new_node)
+{
+  /* return pointer to list unchanged if new_node doesn't exist*/
+  if (!new_node)
+    return first;
+  /* if current doesn't exist, new_node is first */
+  if (!current)
+  {
+    new_node->previous = 0;
+    new_node->next =0;
+    first = new_node;
+    return first;
+  }
+
+  if (current->next)  /* avoid error if at end of list */
+    current->next->previous = new_node;
+  new_node->next = current->next;
+  current->next = new_node;
+  new_node->previous = current;
+  return first;
+}
+
+
+
+/* adds the new node to the end of the list */
+MC_MathQuestion* append_node(MC_MathQuestion* list, MC_MathQuestion* new_node)
+{
+  MC_MathQuestion* ptr;
+  /* return pointer to list unchanged if new_node doesn't exist*/
+  if (!new_node)
+  {
+    return list;
+  }
+
+  /* if list does not exist, new_node is the first (and only) node */
+  if (!list)
+  {
+    return new_node;
+  }
+  /* otherwise, go to end of list */
+  ptr = list;
+  while (ptr->next)
+  {
+    ptr = ptr->next;
+  }
+
+  ptr->next = new_node;
+  new_node->previous = ptr;
+  new_node->next = 0;
+  return list;
+}
+
+
+
+/* this takes the node out of the list but does not delete it */
+/* and returns a pointer to the top of the modified list  */
+MC_MathQuestion* remove_node(MC_MathQuestion* first, MC_MathQuestion* n)
+{
+  if (!n || !first)
+    return first;
+  /* special case if first node being removed */
+  if (n == first)
+     first = first->next;
+
+  if (n->previous)
+    n->previous->next = n->next;
+  if (n->next)
+      n->next->previous = n->previous;
+  n->previous = 0;
+  n->next = 0;
+  return first;
+}
+
+
+
+/* frees memory for entire list and returns null pointer */
+MC_MathQuestion* delete_list(MC_MathQuestion* list)
+{
+  MC_MathQuestion* tmp_ptr;
+  while (list)
+  {
+    tmp_ptr = list->next;
+    free_node (list);
+    list = tmp_ptr;
+  }
+  return list;
+}
+
+
+
+void print_list(FILE* fp, MC_MathQuestion* list)
+{
+  if (!list)
+  {
+    fprintf(fp, "\nprint_list(): list empty or pointer invalid\n");
+    return;
+  }
+
+  MC_MathQuestion* ptr = list;
+  while (ptr)
+  {
+    fprintf(stderr, "%s\n", ptr->card.formula_string);
+    ptr = ptr->next;
+  }
+}
+
+void print_vect_list(FILE* fp, MC_MathQuestion** vect, int length)
+{
+  if (!vect)
+  {
+    fprintf(fp, "\nprint_vect_list(): list empty or pointer invalid\n");
+    return;
+  }
+
+  int i = 0;
+  mcdprintf("Entering print_vect_list()\n");
+  for(i = 0; i < length; i++)
+    fprintf(fp, "%s\n", vect[i]->card.formula_string);
+
+  mcdprintf("Leaving print_vect_list()\n");
+}
+
+#ifdef MC_DEBUG
+void print_card(MC_FlashCard card)
+{
+  printf("\nprint_card():");
+  printf("formula_string = %s\nanswer_string = %s\ndifficulty = %d\n\n",
+         card.formula_string,
+         card.answer_string,
+         card.difficulty);
+}
+
+/* This sends the values of all "global" counters and the */
+/* lengths of the question lists to stdout - for debugging */
+void print_counters(void)
+{
+  printf("\nquest_list_length = \t%d", quest_list_length);
+  printf("\nlist_length(question_list) = \t%d", list_length(question_list));
+  printf("\nstarting_length = \t%d", starting_length);
+  printf("\nunanswered = \t%d", unanswered);
+  printf("\nanswered_correctly = \t%d", answered_correctly);
+  printf("\nanswered_wrong = \t%d", answered_wrong);
+  printf("\nlist_length(wrong_quests) = \t%d", list_length(wrong_quests));
+  printf("\nquestions_pending = \t%d", questions_pending);
+}
+
+// /* a "copy constructor", so to speak */
+// /* FIXME should properly return newly allocated list if more than one node DSB */
+// MC_MathQuestion* create_node_copy(MC_MathQuestion* other)
+// {
+//   MC_MathQuestion* ret = allocate_node();
+//   if (ret)
+//     copy_card(&(other->card), &(ret->card) );
+//   return ret;
+// }
+// 
+// /* FIXME take care of strings */
+// 
+// MC_FlashCard create_card_from_node(MC_MathQuestion* node)
+// {
+//   MC_FlashCard fc;
+//   if (!node)
+//     return DEFAULT_CARD;
+//   fc = MC_AllocateFlashcard();
+//   copy_card(&(node->card), &fc);
+//   return fc;
+// }
+#endif
+
+int list_length(MC_MathQuestion* list)
+{
+  int length = 0;
+  while (list)
+  {
+    length++;
+    list = list->next;
+  }
+  return length;
+}
+
+
+
+
+
+
+/* This is a new implementation written in an attempt to avoid       */
+/* the O(n^2) performance problems seen with the old randomization   */
+/* function. The list is created as a vector, but is for now still   */
+/* made a linked list to minimize changes needed elsewhere.          */
+/* The argument is a pointer to the top of the old list.  This extra */
+/* level of indirection allows the list to be shuffled "in-place".   */
+/* The function returns 1 if successful, 0 on errors.                */
+
+static int randomize_list(MC_MathQuestion** old_list)
+{
+  MC_MathQuestion* old_tmp = *old_list;
+  MC_MathQuestion** tmp_vect = NULL;
+
+  int i = 0;
+  if (!old_list || !*old_list) //invalid/empty list
+    return 0;
+  
+  int old_length = list_length(old_tmp);
+
+  /* set random seed: */
+  srand(time(0));
+
+
+  /* Allocate vector and set ptrs to nodes in old list: */
+
+  /* Allocate a list of pointers, not space for the nodes themselves: */
+  tmp_vect = (MC_MathQuestion**)malloc(sizeof(MC_MathQuestion*) * old_length);
+  /* Set each pointer in the vector to the corresponding node: */
+  for (i = 0; i < old_length; i++)
+  {
+    tmp_vect[i] = old_tmp;
+    tmp_vect[i]->randomizer = rand();
+    old_tmp = old_tmp->next;
+  }
+
+  /* Now simply sort on 'tmp_vect[i]->randomizer' to shuffle list: */
+  qsort(tmp_vect, old_length,
+        sizeof(MC_MathQuestion*),
+        comp_randomizer);
+
+  /* Re-create pointers to provide linked-list functionality:      */
+  /* (stop at 'old_length-1' because we dereference tmp_vect[i+1]) */
+  for(i = 0; i < old_length - 1; i++)
+  {
+    if (!tmp_vect[i])
+    {
+      fprintf(stderr, "Invalid pointer!\n");
+      return 0;
+    }
+    tmp_vect[i]->next = tmp_vect[i+1];
+    tmp_vect[i+1]->previous = tmp_vect[i];
+  }
+  /* Handle end cases: */
+  tmp_vect[0]->previous = NULL;
+  tmp_vect[old_length-1]->next = NULL;
+
+  /* Now arrange for arg pointer to indirectly point to first element! */
+  *old_list = tmp_vect[0];
+  free(tmp_vect);
+  return 1;
+}
+
+
+
+/* This is needed for qsort(): */
+int comp_randomizer (const void* a, const void* b)
+{
+
+  int int1 = (*(const struct MC_MathQuestion **) a)->randomizer;
+  int int2 = (*(const struct MC_MathQuestion **) b)->randomizer;
+
+  if (int1 > int2)
+    return 1;
+  else if (int1 == int2)
+    return 0;
+  else
+    return -1;
+}
+
+MC_MathQuestion* pick_random(int length, MC_MathQuestion* list)
+{
+  int i;
+  int rand_node;
+
+  /* set random seed DSB */
+  srand(time(0));
+
+  /* if length is zero, get out to avoid divide-by-zero error */
+  if (0 == length)
+  {
+    return list;
+  }
+
+  rand_node = rand() % length;
+
+  for (i=1; i < rand_node; i++)
+  {
+    if (list)
+     list = list->next;
+  }
+
+  return list;
+}
+
+/* compares fields other than pointers */
+int compare_node(MC_MathQuestion* first, MC_MathQuestion* other)
+{
+  if (!first || !other)
+    return 0;
+  if (compare_card(&(first->card), &(first->card) ) ) //cards are equal
+    return 1;
+  else
+    return 0;
+}
+
+/* check to see if list already contains an identical node */
+int already_in_list(MC_MathQuestion* list, MC_MathQuestion* ptr)
+{
+  if (!list || !ptr)
+    return 0;
+
+  while (list)
+  {
+    if (compare_node(list, ptr))
+      return 1;
+    list = list->next;
+  }
+  return 0;
+}
+
+// /* to prevent option settings in math_opts from getting set to */
+// /* values other than 0 or 1                                    */
+// int int_to_bool(int i)
+// {
+//   if (i)
+//     return 1;
+//   else
+//     return 0;
+// }
+
+// /* prevent values from getting into math_opts that are outside */
+// /* the range that can be handled by the program (i.e. more     */
+// /* than three digits; also disallow negatives if that has been */
+// /* selected.                                                   */
+// int sane_value(int i)
+// {
+//   if (i > MC_GLOBAL_MAX)
+//     i = MC_GLOBAL_MAX;
+//   else if (i < -MC_GLOBAL_MAX)
+//     i = -MC_GLOBAL_MAX;
+// 
+//   if (i < 0
+//    && math_opts
+//    && !math_opts->iopts[ALLOW_NEGATIVES])
+//   {
+//     i = 0;
+//   }
+// 
+//   return i;
+// }
+
+// int abs_value(int i)
+// {
+//   if (i > 0)
+//     return i;
+//   else
+//     return -i;
+// }
+
+int log10i(int i) //base 10 logarithm for ints
+{
+  int j;
+  for (j = 0; i > 0; i /= 10, ++j);
+  return j;
+}
+
+/* Compares two floats (needed for sorting in MC_MedianTimePerQuestion) */
+int floatCompare(const void *v1,const void *v2)
+{
+  float f1,f2;
+
+  f1 = *((float *) v1);
+  f2 = *((float *) v2);
+
+  if (f1 < f2)
+    return -1;
+  else if (f1 > f2)
+    return 1;
+  else
+    return 0;
+}
+
+
+
+/****************************************************
+Functions for new mathcards architecture
+****************************************************/
+
+void copy_card(const MC_FlashCard* src, MC_FlashCard* dest)
+{
+  if (!src || !dest)
+    return;
+  mcdprintf("Copying '%s' to '%s', ", src->formula_string,dest->formula_string);
+  mcdprintf("copying '%s' to '%s'\n", src->answer_string, dest->answer_string);
+  strncpy(dest->formula_string, src->formula_string, max_formula_size);
+  strncpy(dest->answer_string, src->answer_string, max_answer_size);
+  mcdprintf("Card is: '%s', '%s'\n", dest->formula_string, dest->answer_string);
+  dest->answer = src->answer;
+  dest->difficulty = src->difficulty;
+}
+
+void free_node(MC_MathQuestion* mq) //no, not that freenode.
+{
+  if (!mq)
+    return;
+  MC_FreeFlashcard(&(mq->card) );
+  free(mq);
+}
+
+MC_MathQuestion* allocate_node()
+{
+  MC_MathQuestion* ret = NULL;
+  ret = malloc(sizeof(MC_MathQuestion) );
+  if (!ret)
+  {
+    printf("Could not allocate space for a new node!\n");
+    return NULL;
+  }
+
+  ret->card = MC_AllocateFlashcard();
+  ret->next = ret->previous = NULL;
+  
+  return ret;
+}
+
+/*
+The function that does the central dirty work pertaining to flashcard
+creation. Extensible to just about any kind of math problem, perhaps
+with the exception of those with multiple answers, such as "8 + 2 > ?"
+Simply specify how the problem is presented to the user, and the
+answer the game should look for, as strings.
+*/
+MC_FlashCard generate_random_flashcard(void)
+{
+  int num;
+  int length;
+  MC_ProblemType pt;
+  MC_FlashCard ret;
+
+  mcdprintf("Entering generate_random_flashcard()\n");
+
+  do
+    pt = rand() % MC_NUM_PTYPES;
+  while ( (pt == MC_PT_TYPING && !MC_GetOpt(TYPING_PRACTICE_ALLOWED) ) ||
+          (pt == MC_PT_ARITHMETIC && !MC_GetOpt(ADDITION_ALLOWED) &&
+                                   !MC_GetOpt(SUBTRACTION_ALLOWED) &&
+                                   !MC_GetOpt(MULTIPLICATION_ALLOWED) &&
+                                   !MC_GetOpt(DIVISION_ALLOWED) ) ||
+          (pt == MC_PT_COMPARISON && !MC_GetOpt(COMPARISON_ALLOWED) )
+        );
+
+  if (pt == MC_PT_TYPING) //typing practice
+  {
+    mcdprintf("Generating typing question\n");
+    ret = MC_AllocateFlashcard();
+    num = rand() % (MC_GetOpt(MAX_TYPING_NUM)-MC_GetOpt(MIN_TYPING_NUM) + 1)
+                  + MC_GetOpt(MIN_TYPING_NUM);
+    snprintf(ret.formula_string, max_formula_size, "%d", num);
+    snprintf(ret.answer_string, max_answer_size, "%d", num);
+    ret.answer = num;
+    ret.difficulty = 10;
+  }
+  else //if (pt == MC_PT_ARITHMETIC)
+  {
+    mcdprintf("Generating arithmetic question");
+    length = rand() % (MC_GetOpt(MAX_FORMULA_NUMS) -
+                       MC_GetOpt(MIN_FORMULA_NUMS) + 1) //avoid div by 0
+                    +  MC_GetOpt(MIN_FORMULA_NUMS);
+    mcdprintf(" of length %d", length);
+    ret = generate_random_ooo_card_of_length(length, 1);
+    #ifdef MC_DEBUG
+    print_card(ret);
+    #endif
+  }
+  //TODO comparison problems (e.g. "6 ? 9", "<")
+
+  mcdprintf("Exiting generate_random_flashcard()\n");
+
+  return ret;
+}
+
+/*
+Recursively generate an order of operations problem. Hopefully this won't
+raise performance issues. Difficulty is calculated based on the length of
+the formula and on the operators used. Problems have a 'base' difficulty of
+1 for binary operations, 3 for 3 numbers, 6, 10, etc. Each operator adds to
+the score: 0, 1, 2, and 3 respectively for addition, subtraction,
+multiplication and division.If reformat is 0, FORMAT_ANS_LAST will be used,
+otherwise a format is chosen at random.
+*/
+MC_FlashCard generate_random_ooo_card_of_length(int length, int reformat)
+{
+  int format = 0;
+  int r1 = 0;
+  int r2 = 0;
+  int ans = 0;
+  char tempstr[max_formula_size];
+  MC_FlashCard ret;
+  MC_Operation op;
+
+  printf(".");
+  if (length > MAX_FORMULA_NUMS)
+    return DEFAULT_CARD;
+  if (length <= 2)
+  {
+    mcdprintf("\n");
+    ret = MC_AllocateFlashcard();
+    for (op = rand() % MC_NUM_OPERS; //pick a random operation
+         MC_GetOpt(op + ADDITION_ALLOWED) == 0; //make sure it's allowed
+         op = rand() % MC_NUM_OPERS);
+
+    mcdprintf("Operation is %c\n", operchars[op]);
+    /*
+    if (op == MC_OPER_ADD)
+    {
+      r1 = rand() % (math_opts->iopts[MAX_AUGEND] - math_opts->iopts[MIN_AUGEND] + 1) + math_opts->iopts[MIN_AUGEND];
+      r2 = rand() % (math_opts->iopts[MAX_ADDEND] - math_opts->iopts[MIN_ADDEND] + 1) + math_opts->iopts[MIN_ADDEND];
+      ans = r1 + r2;
+    }
+    else if (op == MC_OPER_SUB)
+    {
+      r1 = rand() % (math_opts->iopts[MAX_MINUEND] - math_opts->iopts[MIN_MINUEND] + 1) + math_opts->iopts[MIN_MINUEND];
+      r2 = rand() % (math_opts->iopts[MAX_SUBTRAHEND] - math_opts->iopts[MIN_SUBTRAHEND] + 1) + math_opts->iopts[MIN_SUBTRAHEND];
+      ans = r1 - r2;
+    }
+    else if (op == MC_OPER_MULT)
+    {
+      r1 = rand() % (math_opts->iopts[MAX_MULTIPLIER] - math_opts->iopts[MIN_MULTIPLIER] + 1) + math_opts->iopts[MIN_MULTIPLIER];
+      r2 = rand() % (math_opts->iopts[MAX_MULTIPLICAND] - math_opts->iopts[MIN_MULTIPLICAND] + 1) + math_opts->iopts[MIN_MULTIPLICAND];
+      ans = r1 * r2;
+    }
+    else if (op == MC_OPER_DIV)
+    {
+      ans = rand() % (math_opts->iopts[MAX_QUOTIENT] - math_opts->iopts[MIN_QUOTIENT] + 1) + math_opts->iopts[MIN_QUOTIENT];
+      r2 = rand() % (math_opts->iopts[MAX_DIVISOR] - math_opts->iopts[MIN_DIVISOR] + 1) + math_opts->iopts[MIN_DIVISOR];
+      if (r2 == 0)
+        r2 = 1;
+      r1 = ans * r2;
+    }
+    */
+    if (op > MC_OPER_DIV || op < MC_OPER_ADD)
+    {
+      mcdprintf("Invalid operator: value %d\n", op);
+      return DEFAULT_CARD;
+    }
+    //choose two numbers in the proper range and get their result
+    
+    else do
+    {
+      r1 = rand() % (math_opts->iopts[MAX_AUGEND+4*op] - math_opts->iopts[MIN_AUGEND+4*op] + 1) + math_opts->iopts[MIN_AUGEND+4*op];    
+      r2 = rand() % (math_opts->iopts[MAX_ADDEND+4*op] - math_opts->iopts[MIN_ADDEND+4*op] + 1) + math_opts->iopts[MIN_ADDEND+4*op]; 
+
+      if (op == MC_OPER_ADD)
+        ans = r1 + r2;
+      if (op == MC_OPER_SUB)
+        ans = r1 - r2;
+      if (op == MC_OPER_MULT)
+        ans = r1 * r2;
+      if (op == MC_OPER_DIV)  
+      {
+        if (r2 == 0)
+          r2 = 1;
+        ret.difficulty = r1;
+        r1 *= r2;
+        ans = ret.difficulty;
+      }
+    } while ( (ans < 0 && !MC_GetOpt(ALLOW_NEGATIVES)) || ans > MC_GetOpt(MAX_ANSWER) );
+
+
+    mcdprintf("Constructing answer_string\n");
+    snprintf(ret.answer_string, max_answer_size+1, "%d", ans);
+    mcdprintf("Constructing formula_string\n");
+    snprintf(ret.formula_string, max_formula_size, "%d %c %d",
+             r1, operchars[op], r2);
+    ret.answer = ans;
+    ret.difficulty = op + 1;
+
+  }
+  else //recurse
+  {
+    ret = generate_random_ooo_card_of_length(length - 1, 0);
+
+    if (strchr(ret.formula_string, '+') || strchr(ret.formula_string, '-') )
+    {
+      //if the expression has addition or subtraction, we can't assume that
+      //introducing multiplication or division will produce a predictable
+      //result, so we'll limit ourselves to more addition/subtraction
+      for (op = rand() % 2 ? MC_OPER_ADD : MC_OPER_SUB;
+           MC_GetOpt(op + ADDITION_ALLOWED) == 0;
+           op = rand() % 2 ? MC_OPER_ADD : MC_OPER_SUB);
+
+    }
+    else
+    {
+      //the existing expression can be treated as a number in itself, so we
+      //can do anything to it and be confident of the result.
+      for (op = rand() % MC_NUM_OPERS; //pick a random operation
+         MC_GetOpt(op + ADDITION_ALLOWED) == 0; //make sure it's allowed
+         op = rand() % MC_NUM_OPERS);
+    }
+    mcdprintf("Next operation is %c,",  operchars[op]);
+
+    //pick the next operand
+    if (op == MC_OPER_ADD)
+    {
+      r1 = rand() % (math_opts->iopts[MAX_AUGEND] - math_opts->iopts[MIN_AUGEND] + 1) + math_opts->iopts[MIN_AUGEND];
+      ret.answer += r1;
+    }
+    else if (op == MC_OPER_SUB)
+    {
+      r1 = rand() % (math_opts->iopts[MAX_SUBTRAHEND] - math_opts->iopts[MIN_SUBTRAHEND] + 1) + math_opts->iopts[MIN_SUBTRAHEND];
+      ret.answer -= r1;
+    }
+    else if (op == MC_OPER_MULT)
+    {
+      r1 = rand() % (math_opts->iopts[MAX_MULTIPLICAND] - math_opts->iopts[MIN_MULTIPLICAND] + 1) + math_opts->iopts[MIN_AUGEND];
+      ret.answer *= r1;
+    }
+    else if (op == MC_OPER_DIV)
+    {
+      r1 = find_divisor(ret.answer);
+      ret.answer /= r1;
+    }
+    else
+    {
+      ; //invalid operator
+    }
+    mcdprintf(" operand is %d\n", r1);
+    mcdprintf("Answer: %d\n", ret.answer);
+
+    //next append or prepend the new number (might need optimization)
+    if (op == MC_OPER_SUB || op == MC_OPER_DIV || //noncommutative, append only
+        rand() % 2)
+    {
+      snprintf(tempstr, max_formula_size, "%s %c %d", //append
+               ret.formula_string, operchars[op], r1);
+      strncpy(ret.formula_string, tempstr, max_formula_size);
+    }
+    else //we're prepending
+    {
+      snprintf(tempstr, max_formula_size, "%d %c %s", //append
+               r1, operchars[op], ret.formula_string);
+      strncpy(ret.formula_string, tempstr, max_formula_size);
+    }
+
+    //finally update the answer and score
+    snprintf(ret.answer_string, max_answer_size, "%d", ret.answer);
+    ret.difficulty += (length - 1) + op;
+  }
+  
+  if (reformat)
+  {
+    mcdprintf("Reformatting...\n");
+    do {
+      format = rand() % MC_NUM_FORMATS;
+    } while (!MC_GetOpt(FORMAT_ANSWER_LAST + format) && 
+             !MC_GetOpt(FORMAT_ADD_ANSWER_LAST + op * 3 + format) );
+   
+    strncat(ret.formula_string, " = ?", max_formula_size - strlen(ret.formula_string) );
+    reformat_arithmetic(&ret, format );     
+  }
+  return ret;
+}
+
+
+
+MC_MathQuestion* generate_list(void)
+{
+  int i, j;
+  int length = MC_GetOpt(AVG_LIST_LENGTH);
+  int cl; //raw length
+  double r1, r2, delta, var; //randomizers for list length
+  MC_MathQuestion* list = NULL;
+  MC_MathQuestion* end_of_list = NULL;
+  MC_MathQuestion* tnode = NULL;
+
+  MC_PrintMathOptions(stdout, 0);
+  if (!(MC_GetOpt(ARITHMETIC_ALLOWED) ||
+      MC_GetOpt(TYPING_PRACTICE_ALLOWED) ||
+      MC_GetOpt(COMPARISON_ALLOWED) ) )
+    return NULL;
+
+  //randomize list length by a "bell curve" centered on average
+  if (length && MC_GetOpt(VARY_LIST_LENGTH) )
+  {
+    r1 = (double)rand() / RAND_MAX / 2 + 0.5; //interval (0, 1)
+    r2 = (double)rand() / RAND_MAX / 2 + 0.5; //interval (0, 1)
+    mcdprintf("Randoms chosen: %5f, %5f\n", r1, r2);
+    delta = sqrt(-2 * log(r1) ) * cos(2 * PI_VAL * r2); //standard normal dist.
+    var = length / 10.0; //variance
+    delta = delta * var;
+    mcdprintf("Delta of average is %5f\n", delta);
+    length += delta;
+    if (length < 0)
+      length = 1; //just in case...
+  }
+
+  if (MC_GetOpt(COMPREHENSIVE)) //generate all
+  {
+    int num_valid_questions; //How many questions the COMPREHENSIVE list specifies
+    int cycles_needed;       //How many times we need to generate it to get enough
+
+    num_valid_questions = calc_num_valid_questions();
+    if(num_valid_questions == 0)
+    {
+      fprintf(stderr, "generate_list() - no valid questions\n");
+      return NULL;
+    }
+
+    cycles_needed = length/num_valid_questions;
+
+    if((cycles_needed * num_valid_questions) < length)
+      cycles_needed++;
+
+    mcdprintf("In generate_list() - COMPREHENSIVE method requested\n");
+    mcdprintf("num_valid_questions = %d\t cycles_needed = %d\n",
+              num_valid_questions, cycles_needed);
+
+    for (i = MC_PT_TYPING; i < MC_NUM_PTYPES; ++i)
+    {
+      if (!MC_GetOpt(i + TYPING_PRACTICE_ALLOWED))
+          continue;
+      for (j = 0; j < cycles_needed; j++)
+        list = add_all_valid(i, list, &end_of_list);
+    }
+
+
+    if (MC_GetOpt(RANDOMIZE) )
+    {
+      mcdprintf("Randomizing list\n");
+      randomize_list(&list);
+    }
+
+    if (length)
+    {
+      cl = list_length(list);
+      // NOTE this should no longer happen - we run the COMPREHENSIVE
+      // generation until we have enough questions.
+      if (length > cl) //if not enough questions, pad out with randoms
+      {
+        mcdprintf("Padding out list from %d to %d questions\n", cl, length);
+        for (i = cl; i < length; ++i)
+        {
+          tnode = malloc(sizeof(MC_MathQuestion) );
+          if(!tnode)
+          {
+            fprintf(stderr, "In generate_list() - allocation failed!\n");
+            delete_list(list);
+            return NULL;
+          }
+
+          tnode->card = generate_random_flashcard();
+          list = insert_node(list, end_of_list, tnode);
+          end_of_list = tnode;
+          mcdprintf("%d...", list_length(list) );
+        }
+      }
+      else if (length < cl) //if too many questions, chop off tail end of list
+      {
+        mcdprintf("Cutting list to %d questions\n", length);
+        end_of_list = find_node(list, length);
+        delete_list(end_of_list->next);
+        end_of_list->next = NULL;
+      }
+    }
+  }
+
+  /* Here we are just generating random questions, one at a */
+  /* time until we have enough                              */
+  else 
+  {
+    mcdprintf("In generate_list() - COMPREHENSIVE method NOT requested\n");
+
+    for (i = 0; i < length; ++i)
+    {
+      tnode = malloc(sizeof(MC_MathQuestion) );
+      if(!tnode)
+      {
+        fprintf(stderr, "In generate_list() - allocation failed!\n");
+        delete_list(list);
+        return NULL;
+      }
+
+      tnode->card = generate_random_flashcard();
+      list = insert_node(list, end_of_list, tnode);
+      end_of_list = tnode;
+    }
+  }
+  return list;
+}
+
+static int compare_card(const MC_FlashCard* a, const MC_FlashCard* b)
+{
+  if (strncmp(a->formula_string, b->formula_string, max_formula_size) )
+    return 1;
+  if (strncmp(a->answer_string, b->answer_string, max_answer_size) )
+    return 1;
+  if (a->answer != b->answer);
+    return 1;
+
+  return 0; //the cards are identical
+}
+
+/* Public functions */
+
+/* allocate space for an MC_Flashcard */
+MC_FlashCard MC_AllocateFlashcard(void)
+{
+  MC_FlashCard ret;
+  mcdprintf("Allocating %d + %d bytes for flashcard\n",
+            max_formula_size + 1, max_answer_size + 1);
+  ret.formula_string = malloc( (max_formula_size + 1) * sizeof(char));
+  ret.answer_string = malloc( (max_answer_size + 1) * sizeof(char));
+  if (!ret.formula_string || !ret.answer_string)
+    {
+    free(ret.formula_string);
+    free(ret.answer_string);
+    printf("Couldn't allocate space for a new flashcard!\n");
+    ret = DEFAULT_CARD;
+    }
+  return ret;
+}
+
+void MC_FreeFlashcard(MC_FlashCard* fc)
+{
+  if (!fc)
+    return;
+//  mcdprintf("Freeing formula_string\n");
+  if (fc->formula_string)
+  {
+    free(fc->formula_string);
+    fc->formula_string = NULL;
+  }
+//  mcdprintf("Freeing answer_string\n");
+  if (fc->answer_string)
+  {
+    free(fc->answer_string);
+    fc->answer_string = NULL;
+  }
+}
+
+unsigned int MC_MapTextToIndex(const char* text)
+{
+  int i;
+  for (i = 0; i < NOPTS; ++i)
+  {
+    if (!strcasecmp(text, MC_OPTION_TEXT[i]) )
+      return i;
+  }
+  mcdprintf("'%s' isn't a math option\n", text);
+  return NOT_VALID_OPTION;
+}
+
+
+//TODO more intuitive function names for access by index vs. by text
+void MC_SetOpt(unsigned int index, int val)
+{
+  if (index >= NOPTS)
+  {
+    mcdprintf("Invalid math option index: %d\n", index);
+    return;
+  }
+
+  /* Do some sanity checks before we throw val into the struct: */
+  switch(index)
+  {
+    /* All the booleans must be 0 or 1: */
+    case PLAY_THROUGH_LIST:
+    case REPEAT_WRONGS:
+    case ALLOW_NEGATIVES:
+    case FORMAT_ANSWER_LAST:
+    case FORMAT_ANSWER_FIRST:
+    case FORMAT_ANSWER_MIDDLE:
+    case FORMAT_ADD_ANSWER_LAST:
+    case FORMAT_ADD_ANSWER_FIRST:
+    case FORMAT_ADD_ANSWER_MIDDLE:
+    case FORMAT_SUB_ANSWER_LAST:
+    case FORMAT_SUB_ANSWER_FIRST:
+    case FORMAT_SUB_ANSWER_MIDDLE:
+    case FORMAT_MULT_ANSWER_LAST:
+    case FORMAT_MULT_ANSWER_FIRST:
+    case FORMAT_MULT_ANSWER_MIDDLE:
+    case FORMAT_DIV_ANSWER_LAST:
+    case FORMAT_DIV_ANSWER_FIRST:
+    case FORMAT_DIV_ANSWER_MIDDLE:
+    case ADDITION_ALLOWED:
+    case SUBTRACTION_ALLOWED:
+    case MULTIPLICATION_ALLOWED:
+    case DIVISION_ALLOWED:
+    case TYPING_PRACTICE_ALLOWED:
+    case ARITHMETIC_ALLOWED:
+    case COMPARISON_ALLOWED:
+    case RANDOMIZE:
+    case COMPREHENSIVE:
+    case VARY_LIST_LENGTH:
+    {
+      /* Reset all non-zero values to one: */
+      if(val)
+      {
+        if(val != 1)
+        {
+          fprintf(stderr, "Warning - parameter %s with invalid value %d, "
+                          "resetting to 1\n", MC_OPTION_TEXT[index], val);
+          val = 1;
+        }
+      }
+      break;
+    }
+
+    /* Parameters concerning numbers of questions */
+    /* must be greater than or equal to zero:     */
+    /* TODO some additional checks would make sense */
+    case QUESTION_COPIES:
+    case COPIES_REPEATED_WRONGS:
+    case MAX_QUESTIONS:
+    case MAX_FORMULA_NUMS:
+    case MIN_FORMULA_NUMS:
+    case AVG_LIST_LENGTH:
+    {
+      /* Reset all negative values to zero: */
+      if(val < 0)
+      {
+        fprintf(stderr, "Warning - parameter %s with invalid value %d, "
+                        "resetting to 0\n", MC_OPTION_TEXT[index], val);
+        val = 0;
+      }
+      break;
+    }
+
+    /* Operand values - make sure they are in displayable range */
+    /* i.e. -999 to 999                                         */ 
+    case MAX_ANSWER:
+    case MIN_AUGEND:
+    case MAX_AUGEND:
+    case MIN_ADDEND:
+    case MAX_ADDEND:
+    case MIN_MINUEND:
+    case MAX_MINUEND:
+    case MIN_SUBTRAHEND:
+    case MAX_SUBTRAHEND:
+    case MIN_MULTIPLIER:
+    case MAX_MULTIPLIER:
+    case MIN_MULTIPLICAND:
+    case MAX_MULTIPLICAND:
+    case MIN_DIVISOR:
+    case MAX_DIVISOR:
+    case MIN_QUOTIENT:
+    case MAX_QUOTIENT:
+    case MIN_TYPING_NUM:
+    case MAX_TYPING_NUM:
+    case MIN_COMPARATOR:
+    case MAX_COMPARATOR:
+    case MIN_COMPARISAND:
+    case MAX_COMPARISAND:
+    {
+      if(val > MC_GLOBAL_MAX)
+      {
+        fprintf(stderr, "Warning - parameter %s with invalid value %d, "
+                       "resetting to %d\n", MC_OPTION_TEXT[index],
+                       val, MC_GLOBAL_MAX);
+        val = MC_GLOBAL_MAX;
+      }
+
+      if(val < (0 - MC_GLOBAL_MAX))
+      {
+        fprintf(stderr, "Warning - parameter %s with invalid value %d, "
+                        "resetting to %d\n", MC_OPTION_TEXT[index],
+                       val, (0 - MC_GLOBAL_MAX));
+        val = (0 - MC_GLOBAL_MAX);
+      }
+
+      break;
+    }
+
+    default:
+        fprintf(stderr, "Warning - in MC_SetOpt() - unrecognized index %d\n",
+                index);
+  }
+  /* Should now be safe to put "sanitized" value into struct: */
+  math_opts->iopts[index] = val;
+}
+
+void MC_SetOp(const char* param, int val)
+{
+  MC_SetOpt(MC_MapTextToIndex(param), val);
+}
+
+int MC_GetOpt(unsigned int index)
+{
+  if (index >= NOPTS)
+  {
+    mcdprintf("Invalid option index: %d\n", index);
+    return MC_MATH_OPTS_INVALID;
+  }
+  if (!math_opts)
+  {
+    printf("Invalid options list!\n");
+    return MC_MATH_OPTS_INVALID;
+  }
+  return math_opts->iopts[index];
+}
+
+int MC_GetOp(const char* param)
+{
+  return MC_GetOpt(MC_MapTextToIndex(param) );
+}
+
+int MC_VerifyOptionListSane(void)
+{
+  return strcmp(MC_OPTION_TEXT[NOPTS], "END_OF_OPTS") == 0;
+}
+
+int MC_MaxFormulaSize(void)
+{
+  return max_formula_size;
+}
+
+int MC_MaxAnswerSize(void)
+{
+  return max_answer_size;
+}
+
+void MC_ResetFlashCard(MC_FlashCard* fc)
+{
+  if (!fc || !fc->formula_string || !fc->answer_string)
+    return;
+  strncpy(fc->formula_string, " ", max_formula_size);
+  strncpy(fc->answer_string, " ", max_answer_size);
+  fc->answer = 0;
+  fc->difficulty = 0;
+}
+
+int MC_FlashCardGood(const MC_FlashCard* fc)
+{
+  return fc && fc->formula_string && fc->answer_string;
+}
+
+int find_divisor(int a)
+{
+  int div = 1; //the divisor to return
+  int realisticpasses = 3; //reasonable time after which a minimum should be met
+  int i;
+  do
+    for (i = 0; i < NPRIMES; ++i) //test each prime
+      if (a % smallprimes[i] == 0)  //if it is a prime factor,
+        if (rand() % (i + 1) == 0) //maybe we'll keep it
+          if (div * smallprimes[i] <= MC_GetOpt(MAX_DIVISOR) ) //if we can,
+            div *= smallprimes[i]; //update our real divisor
+  //keep going if the divisor is too small
+  while (div < MC_GetOpt(MIN_DIVISOR) && --realisticpasses); 
+  
+  return div;
+}
+
+
+//Computes (approximately) the number of questions that will be returned
+//by add_all_valid() as specified by the current options. This does not 
+//take into account screening out of invalid questions, such
+//as divide-by-zero and questions like "0 x ? = 0".
+static int calc_num_valid_questions(void)
+{
+  int total_questions = 0;
+  int k = 0;
+  //First add the number of typing questions
+  if (MC_GetOpt(TYPING_PRACTICE_ALLOWED))
+    total_questions += (MC_GetOpt(MAX_TYPING_NUM) - MC_GetOpt(MIN_TYPING_NUM));
+
+  //Now add how many questions we will have for each operation:
+  for (k = MC_OPER_ADD; k < MC_NUM_OPERS; ++k)
+  {
+    int num_this_oper = 0;
+    int formats_this_oper = 0;
+
+    if (!MC_GetOpt(k + ADDITION_ALLOWED) )
+      continue;
+
+    //calculate number of ordered pairs of first and second operands:
+    //note the "+ 1" is due to the ranges being inclusive
+    num_this_oper = (MC_GetOpt(MAX_AUGEND + 4 * k) - MC_GetOpt(MIN_AUGEND + 4 * k) + 1)
+                    *
+                    (MC_GetOpt(MAX_ADDEND + 4 * k) - MC_GetOpt(MIN_ADDEND + 4 * k) + 1);
+    //check what formats are allowed
+    if (MC_GetOpt(FORMAT_ANSWER_LAST) && MC_GetOpt(FORMAT_ADD_ANSWER_LAST + k * 3))
+      formats_this_oper++;
+    if (MC_GetOpt(FORMAT_ANSWER_FIRST) && MC_GetOpt(FORMAT_ADD_ANSWER_FIRST + k * 3))
+      formats_this_oper++;
+    if (MC_GetOpt(FORMAT_ANSWER_MIDDLE) && MC_GetOpt(FORMAT_ADD_ANSWER_MIDDLE + k * 3))
+      formats_this_oper++;
+    //Get total of e.g. addition questions:
+    num_this_oper *= formats_this_oper;
+    //add to overall total:
+    total_questions += num_this_oper;
+  }
+
+  //TODO will also need to count up the COMPARISON questions once
+  //they are implemented
+  {
+  }
+
+  mcdprintf("calc_num_valid_questions():\t%d\n", total_questions);
+  return total_questions;
+}
+
+
+//NOTE end_of_list** needs to be doubly indirect because otherwise the end does not
+//get updated in the calling code
+//NOTE the difficulty is set as add = 1, sub = 2, mult = 3, div = 4, plus a 2 point
+//bonus if the format is a "missing number".
+MC_MathQuestion* add_all_valid(MC_ProblemType pt, MC_MathQuestion* list, MC_MathQuestion** end_of_list)
+{
+  int i, j;
+  int ans = 0, tmp;
+  MC_Operation k;
+  MC_MathQuestion* tnode;
+
+  mcdprintf("Entering add_all_valid(%d)\n", pt);
+  mcdprintf("List already has %d questions\n", list_length(list));
+
+  //make sure this problem type is actually allowed
+  if (!MC_GetOpt(pt + TYPING_PRACTICE_ALLOWED) )
+    return list;
+
+  //add all typing questions in range
+  if (pt == MC_PT_TYPING)
+  {
+    mcdprintf("Adding typing...\n");
+    for (i = MC_GetOpt(MIN_TYPING_NUM); i <= MC_GetOpt(MAX_TYPING_NUM); ++i)
+    {
+      mcdprintf("(%d)\n", i);
+      tnode = allocate_node();
+      if(!tnode)
+      {
+        fprintf(stderr, "In add_all_valid() - allocate_node() failed!\n");
+        delete_list(list);
+        return NULL;
+      }
+
+      snprintf(tnode->card.formula_string, max_formula_size, "%d", i);
+      snprintf(tnode->card.answer_string, max_formula_size, "%d", i);
+      tnode->card.difficulty = 1;
+      list = insert_node(list, *end_of_list, tnode);
+      *end_of_list = tnode;
+    }
+  }
+
+  //add all allowed arithmetic questions
+  else if (MC_PT_ARITHMETIC)
+  {
+    mcdprintf("Adding arithmetic...\n");
+
+    // The k loop iterates through the four arithmetic operations:
+    // k = 0 means addition
+    // k = 1 means subtraction
+    // k = 2 means multiplication
+    // k = 3 means division
+    for (k = MC_OPER_ADD; k < MC_NUM_OPERS; ++k)
+    {
+      if (!MC_GetOpt(k + ADDITION_ALLOWED) )
+        continue;
+      mcdprintf("\n*%d*\n", k);
+
+      // The i loop iterates through the first value in the question:
+      for (i = MC_GetOpt(MIN_AUGEND + 4 * k); i <= MC_GetOpt(MAX_AUGEND + 4 * k); ++i)
+      {
+        mcdprintf("\n%d:\n", i);
+
+        // The j loop iterates through the second value in the question:
+        for (j = MC_GetOpt(MIN_ADDEND + 4 * k); j <= MC_GetOpt(MAX_ADDEND + 4 * k); ++j)
+        {
+          // Generate the third number according to the operation.
+          // Although it is called "ans", it will not be the actual
+          // answer if it is a "missing number" type problem
+          // (e.g. "3 x ? = 12")
+          // We also filter out invalid questions here
+          switch (k)
+          {
+            case MC_OPER_ADD:
+            {
+              ans = i + j;
+              // throw anything over MAX_ANSWER
+              if (ans > MC_GetOpt(MAX_ANSWER))
+                continue;
+              break;
+            }
+            case MC_OPER_SUB:
+            {
+              ans = i - j;
+              // throw out negatives if they aren't allowed:
+              if (ans < 0 && !MC_GetOpt(ALLOW_NEGATIVES))
+                continue;
+              // throw anything over MAX_ANSWER
+              if (ans > MC_GetOpt(MAX_ANSWER))
+                continue;
+              break;
+            }
+            case MC_OPER_MULT:
+            {
+              ans = i * j;
+              // throw anything over MAX_ANSWER
+              if (ans > MC_GetOpt(MAX_ANSWER))
+                continue;
+              break;
+            }
+            case MC_OPER_DIV:
+            {
+               // throw anything over MAX_ANSWER
+              if (i * j > MC_GetOpt(MAX_ANSWER))
+                continue;
+
+              tmp = i;
+              i *= j;
+              ans = j;
+              j = tmp;
+              break;
+            }
+            default:
+              fprintf(stderr, "Unrecognized operation type: %d\n", k);
+              continue;
+          }
+
+          mcdprintf("Generating: %d %c %d = %d\n", i, operchars[k], j, ans);
+
+          //add each format, provided it's allowed in general and for this op
+
+          // Questions like "a + b = ?"
+          if (MC_GetOpt(FORMAT_ANSWER_LAST) && MC_GetOpt(FORMAT_ADD_ANSWER_LAST + k * 3))
+          {
+            // Avoid division by zero:
+            if (k == MC_OPER_DIV && j == 0)
+            {
+              // need to restore i and j to original values so loop works:
+              j = ans;
+              i = tmp;
+              continue;
+            }
+
+            tnode = allocate_node();
+            if(!tnode)
+            {
+              fprintf(stderr, "In add_all_valid() - allocate_node() failed!\n");
+              delete_list(list);
+              return NULL;
+            }
+
+            snprintf(tnode->card.answer_string, max_formula_size, "%d", ans);
+            snprintf(tnode->card.formula_string, max_formula_size,
+                     "%d %c %d = ?", i, operchars[k], j);
+            tnode->card.difficulty = k + 1;
+            list = insert_node(list, *end_of_list, tnode);
+            *end_of_list = tnode;
+          }
+
+
+          // Questions like "? + b = c"
+          if (MC_GetOpt(FORMAT_ANSWER_FIRST) && MC_GetOpt(FORMAT_ADD_ANSWER_FIRST + k * 3) )
+          {
+            // Avoid questions with indeterminate answer:
+            // e.g. "? x 0 = 0"
+            if (k == MC_OPER_MULT && j == 0)
+            {
+              continue;
+            }
+            // Avoid division by zero:
+            if (k == MC_OPER_DIV && j == 0)
+            {
+              // need to restore i and j to original values so loop works:
+              j = ans;
+              i = tmp;
+              continue;
+            }
+
+            tnode = allocate_node();
+            if(!tnode)
+            {
+              fprintf(stderr, "In add_all_valid() - allocate_node() failed!\n");
+              delete_list(list);
+              return NULL;
+            }
+
+            snprintf(tnode->card.answer_string, max_formula_size, "%d", i);
+            snprintf(tnode->card.formula_string, max_formula_size,
+                     "? %c %d = %d", operchars[k], j, ans);
+            tnode->card.difficulty = k + 3;
+            list = insert_node(list, *end_of_list, tnode);
+            *end_of_list = tnode;
+          }
+
+
+          // Questions like "a + ? = c"
+          if (MC_GetOpt(FORMAT_ANSWER_MIDDLE) && MC_GetOpt(FORMAT_ADD_ANSWER_MIDDLE + k * 3))
+          {
+            // Avoid questions with indeterminate answer:
+            // e.g. "0 x ? = 0"
+            if (k == MC_OPER_MULT && i == 0)
+              continue;
+
+            // e.g. "0 / ? = 0"
+            if (k == MC_OPER_DIV && i == 0)
+            {
+              // need to restore i and j to original values so loop works:
+              j = ans;
+              i = tmp;
+              continue;
+            }
+
+            tnode = allocate_node();
+            if(!tnode)
+            {
+              fprintf(stderr, "In add_all_valid() - allocate_node() failed!\n");
+              delete_list(list);
+              return NULL;
+            }
+
+            snprintf(tnode->card.answer_string, max_formula_size, "%d", j);
+            snprintf(tnode->card.formula_string, max_formula_size,
+                     "%d %c ? = %d", i, operchars[k], ans);
+            tnode->card.difficulty = k + 3;
+            list = insert_node(list, *end_of_list, tnode);
+            *end_of_list = tnode;
+          }
+          //If we divided, reset i and j so loop works correctly
+          if (k == MC_OPER_DIV)
+          {
+            j = ans;
+            i = tmp;
+            mcdprintf("resetting to %d %d\n", j, i);
+          }
+        }
+      }
+    }
+  }
+  //add all comparison questions (TODO implement them!)
+  else if (pt == MC_PT_COMPARISON)
+  {
+    for (i = MC_GetOpt(MIN_COMPARATOR); i < MC_GetOpt(MAX_COMPARATOR); ++i)
+    {
+      for (j = MC_GetOpt(MIN_COMPARISAND); j < MC_GetOpt(MAX_COMPARISAND); ++j)
+      {
+        tnode = allocate_node();
+        if(!tnode)
+        {
+          fprintf(stderr, "In add_all_valid() - allocate_node() failed!\n");
+          delete_list(list);
+          return NULL;
+        }
+
+        snprintf(tnode->card.formula_string, max_formula_size, "%d ? %d", i,j);
+        snprintf(tnode->card.answer_string, max_formula_size,
+                 i < j ? "<" : 
+                 i > j ? ">" : 
+                         "=");
+        tnode->card.difficulty = 1;
+        list = insert_node(list, *end_of_list, tnode);
+        *end_of_list = tnode;
+      }
+    }
+  }
+  mcdprintf("Exiting add_all_valid()\n");  
+  mcdprintf("List now has %d questions\n\n", list_length(list));
+
+  return list;
+}
+
+MC_MathQuestion* find_node(MC_MathQuestion* list, int num)
+{
+  while (--num > 0 && list)
+    list = list->next;
+  return list;
+}
+
+void reformat_arithmetic(MC_FlashCard* card, MC_Format f)
+{
+  int i, j;
+  char* beg = 0;
+  char* end = 0;
+  char nans[max_answer_size];
+  char nformula[max_formula_size + max_answer_size]; //gets a bit larger than usual in the meantime
+  
+  {
+    //snprintf(nans, max_answer_size, "%s", card->answer_string);
+   
+    //insert old answer where question mark was
+    for (i = 0, j = 0; card->formula_string[j] != '?'; ++i, ++j)
+      nformula[i] = card->formula_string[j];
+    i += snprintf(nformula + i, max_answer_size - 1, "%s", card->answer_string);
+    snprintf(nformula + i, max_formula_size - i, "%s", card->formula_string + j + 1);
+
+    //replace the new answer with a question mark
+    if (f == MC_FORMAT_ANS_LAST)
+      beg = strrchr(nformula, ' ') + 1;
+    if (f == MC_FORMAT_ANS_FIRST)
+      beg = nformula;
+    if (f == MC_FORMAT_ANS_MIDDLE)
+      beg = strchr(nformula, ' ') + 3;
+    end = strchr(beg + 1, ' ');
+    if (!end)
+      end = "";
+    //we now have beg = first digit of number to replace, end = the char after
+    sscanf(beg, "%s", nans);
+    *beg = 0; //sequester the first half of the string
+    snprintf(card->formula_string, max_formula_size, "%s?%s", nformula, end);
+    snprintf(card->answer_string, max_answer_size, "%s", nans);
+    card->answer = atoi(card->answer_string);
+  }
+}


Property changes on: tuxmath/branches/lan/server/mathcards.c
___________________________________________________________________
Added: svn:executable
   + *

Added: tuxmath/branches/lan/server/mathcards.h
===================================================================
--- tuxmath/branches/lan/server/mathcards.h	                        (rev 0)
+++ tuxmath/branches/lan/server/mathcards.h	2009-06-11 21:13:31 UTC (rev 1032)
@@ -0,0 +1,296 @@
+/*
+
+        mathcards.h
+
+        Description: contains headers for a flashcard-type math game.
+        This is a sort of interface-independent backend that could be used with a different
+        user interface. Developed as an enhancement to Bill Kendrick's "Tux of Math Command"
+        (aka tuxmath).  If tuxmath were a C++ program, this would be a C++ class.
+
+        Author: David Bruce <dbruce at tampabay.rr.com>, (C) 2006
+
+        Copyright: See COPYING file that comes with this distribution (briefly, GNU GPL version 2 or later)
+
+*/
+#ifndef MATHCARDS_H
+#define MATHCARDS_H
+
+#define MC_DEBUG
+#ifdef MC_DEBUG
+#define mcdprintf(...) printf(__VA_ARGS__)
+#else
+#define mcdprintf(...) 0
+#endif
+
+#define MC_USE_NEWARC
+
+/* different classes of problems TuxMath will ask */
+typedef enum _MC_ProblemType {
+  MC_PT_TYPING,
+  MC_PT_ARITHMETIC,
+  MC_PT_COMPARISON,
+  MC_NUM_PTYPES
+} MC_ProblemType;
+
+/* type of math operation used in an arithmetic question */
+typedef enum _MC_Operation {
+  MC_OPER_ADD,
+  MC_OPER_SUB,
+  MC_OPER_MULT,
+  MC_OPER_DIV,
+  MC_NUM_OPERS
+} MC_Operation;
+
+/* math question formats: */
+typedef enum _MC_Format {
+  MC_FORMAT_ANS_LAST,     /* a + b = ? */
+  MC_FORMAT_ANS_FIRST,    /* ? + b = c */
+  MC_FORMAT_ANS_MIDDLE,    /* a + ? = c */
+  MC_NUM_FORMATS
+} MC_Format;
+
+
+/*
+Indices for the various integer options. These are NOT the actual values!
+Actual values are accessed as such: options.iopts[PLAY_THROUGH_LIST] = val;
+Creating additional [integral] options is now centralized--it should only
+be necessary to add to this list, the list of text, and the list of
+defaults. (Besides actually using the new options!)
+*/
+enum {
+  NOT_VALID_OPTION = -1     ,
+  PLAY_THROUGH_LIST = 0     , /* play until all questions answered correctly */
+  QUESTION_COPIES           , /* # times each question is put in list */
+  REPEAT_WRONGS             , /* reuse incorrectly answered questions or not */
+  COPIES_REPEATED_WRONGS    , /* how many copies of an incorrectly answered question to re-insert*/
+  ALLOW_NEGATIVES           ,
+  MAX_ANSWER                ,
+  MAX_QUESTIONS             ,
+  MAX_FORMULA_NUMS          ,
+  MIN_FORMULA_NUMS          ,
+
+  //NOTE: Do _not_ rearrange the FORMAT values because the functions
+  //rely on index arithmetic to iterate through these, and will be
+  //broken if the relative position changes!
+  FORMAT_ANSWER_LAST        , /* question format is: a + b = ? */
+  FORMAT_ANSWER_FIRST       , /* question format is: ? + b = c */
+  FORMAT_ANSWER_MIDDLE      , /* question format is: a + ? = c */
+  FORMAT_ADD_ANSWER_LAST    , /* a + b = ?    */
+  FORMAT_ADD_ANSWER_FIRST   , /* ? + b = c    */
+  FORMAT_ADD_ANSWER_MIDDLE  , /* a + ? = c    */
+  FORMAT_SUB_ANSWER_LAST    , /* a - b = ?    */
+  FORMAT_SUB_ANSWER_FIRST   , /* ? - b = c    */
+  FORMAT_SUB_ANSWER_MIDDLE  , /* a - ? = c    */
+  FORMAT_MULT_ANSWER_LAST   , /* a * b = ?    */
+  FORMAT_MULT_ANSWER_FIRST  , /* ? * b = c    */
+  FORMAT_MULT_ANSWER_MIDDLE , /* a * ? = c    */
+  FORMAT_DIV_ANSWER_LAST    , /* a / b = ?    */
+  FORMAT_DIV_ANSWER_FIRST   , /* ? / b = c    */
+  FORMAT_DIV_ANSWER_MIDDLE  , /* a / ? = c    */
+
+  ADDITION_ALLOWED          ,
+  SUBTRACTION_ALLOWED       ,
+  MULTIPLICATION_ALLOWED    ,
+  DIVISION_ALLOWED          ,
+  TYPING_PRACTICE_ALLOWED   ,
+  ARITHMETIC_ALLOWED        ,
+  COMPARISON_ALLOWED        ,
+
+  MIN_AUGEND                , /* augend + addend = sum */
+  MAX_AUGEND                ,
+  MIN_ADDEND                ,
+  MAX_ADDEND                ,
+
+  MIN_MINUEND               , /* minuend - subtrahend = difference */
+  MAX_MINUEND               ,
+  MIN_SUBTRAHEND            ,
+  MAX_SUBTRAHEND            ,
+
+  MIN_MULTIPLIER            , /* multiplier * multiplicand = product */
+  MAX_MULTIPLIER            ,
+  MIN_MULTIPLICAND          ,
+  MAX_MULTIPLICAND          ,
+
+  MIN_DIVISOR               , /* dividend/divisor = quotient */
+  MAX_DIVISOR               , /* note - generate_list() will prevent */
+  MIN_QUOTIENT              , /* questions with division by zero.    */
+  MAX_QUOTIENT              ,
+
+  MIN_TYPING_NUM            , /* range for "typing tutor" mode, for  */
+  MAX_TYPING_NUM            , /* kids just learning to use keyboard. */
+
+  MIN_COMPARATOR            , /* left comparison operand */
+  MAX_COMPARATOR            ,
+  MIN_COMPARISAND           , /* right comparison operannd */
+  MAX_COMPARISAND           ,
+
+  RANDOMIZE                 , /* whether to shuffle cards */
+
+  COMPREHENSIVE             , /* whether to generate all questions 'in order' */
+  AVG_LIST_LENGTH           , /* the average number of questions in a list */
+  VARY_LIST_LENGTH          , /* whether to randomly adjust list length */
+
+  NOPTS
+};
+
+extern const char* const MC_OPTION_TEXT[];
+extern const int MC_DEFAULTS[];
+extern const char operchars[MC_NUM_OPERS];
+
+/* default values for math_options */
+#define MC_MAX_DIGITS 3 
+#define MC_GLOBAL_MAX 999          /* This is the largest absolute value that */
+                                   /* can be entered for math question values.*/
+#define MC_MATH_OPTS_INVALID -9999 /* Return value for accessor functions     */
+                                   /* if math_opts not valid                  */
+//#define DEFAULT_FRACTION_TO_KEEP 1
+
+
+typedef struct _MC_Options
+{
+  int iopts[NOPTS];
+} MC_Options;
+
+#ifndef MC_USE_NEWARC
+/* struct for individual "flashcard" */
+typedef struct MC_FlashCard {
+  int num1;
+  int num2;
+  int num3;
+  int operation;
+  int format;
+  char formula_string[MC_FORMULA_LEN];
+  char answer_string[MC_ANSWER_LEN];
+} MC_FlashCard;
+#else
+/* experimental struct for a more generalized flashcard */
+typedef struct _MC_FlashCard {
+  char* formula_string;
+  char* answer_string;
+  int answer;
+  int difficulty;
+} MC_FlashCard;
+#endif
+
+/* struct for node in math "flashcard" list */
+typedef struct MC_MathQuestion {
+  MC_FlashCard card;
+  struct MC_MathQuestion* next;
+  struct MC_MathQuestion* previous;
+  int randomizer;
+} MC_MathQuestion;
+
+
+/* "public" function prototypes: these functions are how */
+/* a user interface communicates with MathCards:         */
+/* TODO provide comments thoroughly explaining these functions */
+
+/*  MC_Initialize() sets up the struct containing all of  */
+/*  settings regarding math questions.  It should be      */
+/*  called before any other function.  Many of the other  */
+/*  functions will not work properly if MC_Initialize()   */
+/*  has not been called. It only needs to be called once, */
+/*  i.e when the program is starting, not at the beginning*/
+/*  of each math game for the player. Returns 1 if        */
+/*  successful, 0 otherwise.                              */
+int MC_Initialize(void);
+
+/*  MC_StartGame() generates the list of math questions   */
+/*  based on existing settings. It should be called at    */
+/*  the beginning of each math game for the player.       */
+/*  Returns 1 if resultant list contains 1 or more        */
+/*  questions, 0 if list empty or not generated           */
+/*  successfully.                                         */
+int MC_StartGame(void);
+
+/*  MC_StartGameUsingWrongs() is like MC_StartGame(),     */
+/*  but uses the incorrectly answered questions from the  */
+/*  previous game for the question list as a review form  */
+/*  of learning. If there were no wrong answers (or no    */
+/*  previous game), it behaves just like MC_StartGame().  */
+/*  FIXME wonder if it should generate a message if the   */
+/*  list is created from settings because there is no     */
+/*  valid wrong question list?                            */
+int MC_StartGameUsingWrongs(void);
+
+/*  MC_NextQuestion() takes a pointer to an allocated     */
+/*  MC_MathQuestion struct and fills in the fields for    */
+/*  use by the user interface program. It basically is    */
+/*  like taking the next flashcard from the pile.         */
+/*  Returns 1 if question found, 0 if list empty/invalid  */
+/*  or if argument pointer is invalid                     */
+int MC_NextQuestion(MC_FlashCard* q);
+
+/*  MC_AnsweredCorrectly() is how the user interface      */
+/*  tells MathCards that the question has been answered   */
+/*  correctly. Returns 1 if no errors.                    */
+int MC_AnsweredCorrectly(MC_FlashCard* q);
+
+/*  MC_NotAnsweredCorrectly() is how the user interface    */
+/*  tells MathCards that the question has not been        */
+/*  answered correctly. Returns 1 if no errors.           */
+int MC_NotAnsweredCorrectly(MC_FlashCard* q);
+
+/*  Like MC_NextQuestion(), but takes "flashcard" from    */
+/*  pile of incorrectly answered questions.               */
+/*  Returns 1 if question found, 0 if list empty/invalid  */
+int MC_NextWrongQuest(MC_FlashCard* q);
+
+/*  Returns 1 if all have been answered correctly,        */
+/* 0 otherwise.                                           */
+int MC_MissionAccomplished(void);
+
+/*  Returns number of questions left (either in list      */
+/*  or "in play")                                         */
+int MC_TotalQuestionsLeft(void);
+
+/*  Returns questions left in list, NOT                   */
+/*  including questions currently "in play".              */
+int MC_ListQuestionsLeft(void);
+
+/*  To keep track of how long students take to answer the */
+/*  questions, one can report the time needed to answer   */
+/*  an individual question:                               */
+int MC_AddTimeToList(float t);
+/*  Note that initialization of the list is handled by    */
+/*  MC_StartGame.                                         */
+
+/*  Tells MathCards to clean up - should be called when   */
+/*  user interface program exits.                         */
+void MC_EndGame(void);
+
+/*  Prints contents of math_opts struct in human-readable   */
+/*  form to given file. "verbose" tells the function to     */
+/*  write a lot of descriptive "help"-type info for each    */
+/*  option (intended to make config files self-documenting).*/
+void MC_PrintMathOptions(FILE* fp, int verbose);
+
+/* Additional functions used to generate game summary files: */
+int MC_PrintQuestionList(FILE* fp);
+int MC_PrintWrongList(FILE* fp);
+int MC_StartingListLength(void);
+int MC_WrongListLength(void);
+int MC_NumAnsweredCorrectly(void);
+int MC_NumNotAnsweredCorrectly(void);
+float MC_MedianTimePerQuestion(void);
+
+/********************************************
+Public functions for new mathcards architecture
+*********************************************/
+/* Return the array index of the given text, e.g. randomize->47 */
+unsigned int MC_MapTextToIndex(const char* text);
+void MC_SetOpt(unsigned int index, int val); //access directly,for internal use
+int MC_GetOpt(unsigned int index);
+void MC_SetOp(const char* param, int val); //access by text, for config reading
+int MC_GetOp(const char* param);
+int MC_VerifyOptionListSane(void);
+int MC_MaxFormulaSize(void); //amount of memory needed to safely hold strings
+int MC_MaxAnswerSize(void);
+MC_FlashCard MC_AllocateFlashcard();
+void MC_FreeFlashcard(MC_FlashCard* fc);
+void MC_ResetFlashCard(MC_FlashCard* fc); //empty flashcard of strings & values
+int MC_FlashCardGood(const MC_FlashCard* fc); //verifies a flashcard is valid
+/* Reorganize formula_string and answer_string to render the same equation
+   in a different format */
+void reformat_arithmetic(MC_FlashCard* card, MC_Format f);
+#endif


Property changes on: tuxmath/branches/lan/server/mathcards.h
___________________________________________________________________
Added: svn:executable
   + *

Added: tuxmath/branches/lan/server/server.c
===================================================================
--- tuxmath/branches/lan/server/server.c	                        (rev 0)
+++ tuxmath/branches/lan/server/server.c	2009-06-11 21:13:31 UTC (rev 1032)
@@ -0,0 +1 @@
+

Modified: tuxmath/branches/lan/src/mathcards.c
===================================================================
--- tuxmath/branches/lan/src/mathcards.c	2009-06-11 19:44:46 UTC (rev 1031)
+++ tuxmath/branches/lan/src/mathcards.c	2009-06-11 21:13:31 UTC (rev 1032)
@@ -22,9 +22,9 @@
 #include <math.h>
 #include <time.h>
 
-//#include "mathcards.h"
-#include "network.h"
+#include "mathcards.h"
 
+
 /* extern'd constants */
 
 const char* const MC_OPTION_TEXT[NOPTS+1] = {




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