bird.c

   1 #include "code.h"
   2
   3 void bird()
   4 {
   5         int steps = 0;
   6
   7         /* x and y can be -1 */
   8         int x, y;
   9
  10         unsigned int i, row, matches = 0;
  11
  12         /* Iterate rows */
  13         for ( row = 0; row < n - m + 1; row++ ) {
  14
  15                 x = 0;
  16
  17                 /* Iterate through results on the same row */
  18                 while ( x != -1 ) {
  19
  20                         x = aho( row, x, 0, n - m );
  21
  22                         steps++;
  23
  24 //                      printf("x row %i column %i\n",row, x);
  25
  26                         /* If a row is found, check the m - 1 rows underneath it for matches */
  27                         if ( x != -1 ) {
  28
  29                                 for ( i = 1; i < m; i++) {
  30                                         /* Optimization: instead of checking against n chars on
  31                                          subsequent rows, just check against the next m chars after x */
  32                                         y = aho( row + i, x, i, x + m );
  33
  34                                         steps++;
  35
  36 //                                      printf("y row %i column %i\n",row + i, y);
  37
  38                                         if ( y != x )
  39                                                 break;
  40
  41                                         /* If we reached to the final line above x without breaking, we have a match */
  42                                         else if ( i == m -1)
  43                                                 matches++;
  44                                 }
  45                                 /* After each attempt,increase the counter + 1 */
  46                                 x++;
  47                         }
  48                 }
  49         }
  50         printf("Bird: %i\n",matches);
  51 }