Created
June 19, 2011 22:03
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brute force string search
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| #include <stdio.h> | |
| #include <string.h> | |
| #include <stdlib.h> | |
| int brutesearch(char *p, char *a) | |
| { | |
| int i, j, M = strlen(p), N = strlen(a); | |
| for (i = 0, j = 0; j < M && i < N; i++, j++) | |
| { | |
| if (a[i] != p[j]) | |
| { | |
| i -= j-1; | |
| j = -1; | |
| i--; | |
| } | |
| } | |
| if (j == M) | |
| { | |
| return i-M; | |
| } else { | |
| return i; | |
| } | |
| } | |
| void printMatch(char *p, char *s) | |
| { | |
| int cnt = brutesearch(p, s); | |
| char *first; | |
| char *rest; | |
| char *middle; | |
| char ESC=27; | |
| first = malloc(sizeof(char) * cnt+1); | |
| middle = malloc(sizeof(char) * strlen(p)+1); | |
| rest = malloc(sizeof(char) * strlen(s)-cnt-strlen(p)+1); | |
| if (cnt < strlen(s)) | |
| { | |
| first = strncpy(first, s,cnt); | |
| middle = strncpy(middle, &s[cnt],strlen(p)); | |
| rest = strncpy(rest,&s[cnt+strlen(p)],strlen(s)-strlen(p)-cnt); | |
| printf("%s", first); | |
| printf("%c[1m",ESC); | |
| printf("%s", middle); | |
| printf("%c[0m",ESC); | |
| printf("%s\n", rest); | |
| } else { | |
| printf("%s matches nothing in %s\n", p, s); | |
| } | |
| free(first); | |
| free(middle); | |
| free(rest); | |
| } | |
| int main(int argc, char* argv[]) | |
| { | |
| if (argc != 3) | |
| { | |
| printf("Usage:\n"); | |
| printf("%s \"pattern\" \"string to search\"\n", argv[0]); | |
| printf("\nExample:\n"); | |
| printf("%s \"hello\" \"hello world\"\n",argv[0]); | |
| return 1; | |
| } else { | |
| printMatch(argv[1],argv[2]); | |
| return 0; | |
| } | |
| } |
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