tower.c

   1 #include <stdlib.h>
   2 #include <stdio.h>
   3
   4 #include "ast.h"
   5 #include "tower.h"
   6
   7 struct fifo_node;
   8 typedef struct fifo_node {
   9   DATA *data;
  10   struct fifo_node *prev;
  11 } fifo_node;
  12
  13 static fifo_node *tower_entrance = NULL;
  14 static fifo_node *tower_exit = NULL;
  15
  16 struct ast *const_true;
  17 struct ast *const_false;
  18 DATA knights[KNIGHT_NUM + 1];
  19
  20 void tower_push(DATA * d)
  21 {
  22   fifo_node *new_node;
  23
  24   if (!tower_entrance) {
  25     tower_entrance = malloc(sizeof (fifo_node));
  26     if (!tower_entrance) {
  27       fprintf(stderr, "Fatal: Could not allocate memory for tower\n");
  28       exit(-1);
  29     }
  30
  31     tower_exit = tower_entrance;
  32     tower_entrance->data = d;
  33     tower_entrance->prev = NULL;
  34   } else {
  35     new_node = malloc(sizeof (fifo_node));
  36     if (!new_node) {
  37       fprintf(stderr, "Fatal: Could not allocate memory for tower\n");
  38       exit(-1);
  39     }
  40
  41     new_node->data = d;
  42     new_node->prev = NULL;
  43     tower_entrance->prev = new_node;
  44     tower_entrance = new_node;
  45   }
  46 }
  47
  48 DATA *tower_pop()
  49 {
  50   DATA *to_return = NULL;
  51   fifo_node *to_delete;
  52
  53   if (!tower_exit)
  54     exit(0);
  55
  56   to_return = tower_exit->data;
  57
  58   if (tower_entrance == tower_exit) {
  59     free(tower_exit);
  60     tower_entrance = NULL;
  61     tower_exit = NULL;
  62   } else {
  63     to_delete = tower_exit;
  64     tower_exit = tower_exit->prev;
  65     free(to_delete);
  66   }
  67
  68   return to_return;
  69 }
  70
  71 void shuffle()
  72 {
  73   int idx, tidx;
  74   DATA t;
  75
  76   for (idx = 1; idx <= KNIGHT_NUM; ++idx) {
  77     tidx = 1 + rand() % KNIGHT_NUM;
  78     t = knights[tidx];
  79     knights[tidx] = knights[idx];
  80     knights[idx] = t;
  81   }
  82 }
  83
  84 void tower_initialize()
  85 {
  86   int i;
  87
  88   const_true = malloc(sizeof (ast));
  89   const_true->type = A_VAR;
  90   const_true->adata.avar = malloc(sizeof (ast_var));
  91   const_true->adata.avar->type = COMPUTED_VAL;
  92   const_true->adata.avar->val.computed_val.type = KBOOL;
  93   const_true->adata.avar->val.computed_val.val = 1;
  94
  95   const_false = malloc(sizeof (ast));
  96   const_false->type = A_VAR;
  97   const_false->adata.avar = malloc(sizeof (ast_var));
  98   const_false->adata.avar->type = COMPUTED_VAL;
  99   const_false->adata.avar->val.computed_val.type = KBOOL;
 100   const_false->adata.avar->val.computed_val.val = 0;
 101
 102   for (i = 1; i <= 9; ++i) {
 103     knights[i].type = KINT;
 104     knights[i].val = i;
 105   }
 106   shuffle();
 107 }