poj3461Oulipo【kmp】

大意：kmp

#include <iostream>
#include <cstdio>
#include <cstring>
using namespace std;

const int maxn = 1000005;

int next[maxn];

void get(char *s) {
    int l = strlen(s);
    int j = 0, k = -1;
    next[0] = -1;
    while(j < l) {
        if(k == -1 || s[j] == s[k]) {
            next[++j] = ++k;
        } else {
            k = next[k];
        }
    }
}

int kmp(char *s1, char *s2) {
    int l1 = strlen(s1), l2 = strlen(s2);
    int i = 0, j = 0;
    int sum = 0;
    get(s2);
    while(i < l1 && j < l2) {
        if(j == -1 || s1[i] == s2[j]) {
            i++; j++;
        } else {
            j = next[j];
        }
        if(j == l2) {
            sum++;
            j = next[j];
        }
    }
    return sum;
}

char s1[maxn], s2[maxn];
int main() {
    int t;
    scanf("%d",&t);
    while(t--) {
        scanf("%s",s1);
        scanf("%s",s2);
//        printf("%s %s
",s1, s2);
        printf("%d
", kmp(s2,s1));
    }
}