baeza.c

   1 #include "code.h"
   2
   3 unsigned int baeza( char **text, char **pattern, int m, int n )
   4 {
   5         unsigned int i, j, row, matches = 0;
   6
   7         int x, y;
   8
   9         /* Iterate every m rows (first check lines 0 to m - 1) */
  10         for ( row = m - 1; row < n; row += m ) {
  11
  12                 /* Search the same row for occurences of the different lines of the pattern */
  13                 for ( i = 0; i < m; i++ ) {
  14
  15                         /* In each row start searching from the begining */
  16                         x = 0;
  17
  18                         while ( x != -1) {
  19
  20                                 /* Check text's row against each pattern's row */
  21                                 x = aho( text, pattern, m, n, row, x, i, n );
  22
  23                                 /* If a row is not found procceed to the next row */
  24                                 if ( x != -1 ) {
  25
  26                                         /* If there is a match at i = 3, check vertically the text above for i = 0-2 and below for 4-m*/
  27
  28                                         /* Check lines above the current */
  29                                         for ( j = 0; j < i; j++ ) {
  30                                                 y = aho( text, pattern, m, n, row - i + j, x, j, x + m );
  31
  32                                                 if ( y != x)
  33                                                         goto newline;
  34                                         }
  35
  36                                         /* Check lines below the current */
  37                                         for ( j = 1; j < m - i; j++ ) {
  38
  39                                                 /* Avoid crashing when x = n or n-1 */
  40                                                 if ( row + j >= n )
  41                                                         goto newline;
  42
  43                                                 y = aho( text, pattern, m, n, row + j, x, i + j, x + m );
  44
  45                                                 if ( y != x )
  46                                                         goto newline;
  47                                         }
  48
  49                                         /* If we reached here we should have a match */
  50                                         matches++;
  51
  52                                 /* If a mismatch is found, don't bother searching for the other y lines */
  53                                 newline:
  54
  55                                         /* Now increase counter to continue search in the same row */
  56                                         x++;
  57                                 }
  58                                 else break;
  59                         }
  60                 }
  61         }
  62         return matches;
  63 }