字符串匹配整理（算法导论 c32, v3）

The naive string-matching algorithm

#include <iostream>
#include <cstring>
#include <cassert>
using namespace std;
char * naive_string_matching(char *text, char *pattern){
int text_length = strlen(text);
int pattern_length = strlen(pattern);
if(text_length < pattern_length)
return NULL;
for(int i = 0; i <= text_length-pattern_length; i++){
if(strncmp(text+i, pattern, pattern_length) == 0)
return text+i;
}
return NULL;
}
int main(){
char *pattern = "zhou";
char *text = "!zhou";
char *r = naive_string_matching(text, pattern);
if(r != NULL)
cout << r << endl;
}

The Rabin-Karp algorithm