[模板][kmp][poj3461][codevs5757]

codevs5757

#include<iostream>
#include<cstdio>
#include<algorithm>
#include<cstring>
using namespace std;
const int MAXN = 1000000 + 50;
char s1[MAXN],s2[MAXN];
int next[MAXN];
int n,m,ans;
int main(){
	scanf("%s",s1 + 1);
	scanf("%s",s2 + 1);
	n = strlen(s1 + 1);
	m = strlen(s2 + 1);
	for(int i = 2;i <= n;i ++){
		int p = next[i - 1];
		while(p && s1[p + 1] != s1[i])//失配，寻找最长前缀
			p = next[p];
		if(s1[p + 1] == s1[i])//
			p ++;
		next[i] = p;
	}
	int p = 0;
	for(int i = 1;i <= m;i ++){
		while(p && s1[p + 1] != s2[i])
			p = next[p];
		if(s1[p + 1] == s2[i])
			p ++;
		if(p == n)
			ans ++;
	}
	printf("%d",ans);
	return 0;
}