array.c

   1 #include <stddef.h>
   2 #include <stdlib.h>
   3 #include <stdio.h>
   4 #include <string.h>
   5 #include "array.h"
   6
   7 /*
   8  * Implements a linear search.
   9  */
  10 int gol_is_live(struct gol_board *const state, int_least32_t x, int_least32_t y,
  11         char *is_live)
  12 {
  13         for (unsigned int i = 0; i < state->n; i += 2) {
  14                 if (state->live_cells[i] == x &&
  15                         state->live_cells[i+1] == y) {
  16                         *is_live = 1;
  17                         return 1;
  18                 }
  19         }
  20         *is_live = 0;
  21         return 1;
  22 }
  23
  24 /*
  25  *  Return values of 0 represent irrecoverable errors. 1 is a success.
  26  */
  27 int gol_vivify(struct gol_board *const state, int_least32_t x, int_least32_t y)
  28 {
  29         int_least32_t *tmp_cells = NULL;
  30         size_t tmp_size = 0;
  31
  32         if (state->n == state->size) {
  33                 tmp_size = 2 * state->size;
  34                 tmp_cells = malloc(tmp_size * sizeof(int_least32_t));
  35                 if (!tmp_cells) {
  36                         return 0;
  37                 }
  38                 memcpy(tmp_cells, state->live_cells,
  39                         state->size * sizeof(int_least32_t));
  40                 state->size = tmp_size;
  41                 free(state->live_cells);
  42                 state->live_cells = tmp_cells;
  43         }
  44
  45         state->live_cells[state->n] = x;
  46         state->live_cells[state->n + 1] = y;
  47
  48         state->n += 2;
  49
  50         if (x > state->max_x) {
  51                 state->max_x = x;
  52         } else if (x < state->min_x) {
  53                 state->min_x = x;
  54         }
  55
  56         if (y > state->max_y) {
  57                 state->max_y = y;
  58         } else if (y < state->min_y) {
  59                 state->min_y = y;
  60         }
  61
  62         return 1;
  63 }