POJ 3461 Oulipo

思考：kmp的灵活运用，模式字符串当匹配成功时候，文本字符串的下一位和模式字符串的第 f[lenw] 开始匹配，详细见代码。

#include <iostream>
#include <cstdio>
#include <cstring>
#include <algorithm>
using namespace std;
const int maxw = 10010;
const int maxt = 1000010;

char w[maxw+5];
char t[maxt+5];
int f[maxw+5];
//Accepted	1716K	94MS	G++	973B	2014-04-05 20:20:23
void getFail() {
    int len = strlen(w);
    f[0] = 0, f[1] = 0;
    int j = 0;
    for(int i = 1; i < len; i++) {
        j = f[i];
        while(j && w[j]!=w[i]) j = f[j];
        f[i+1] = w[j]==w[i] ? j+1 : 0;
    }
}

int match() {
    getFail();
    int cnt = 0;
    int lenw = strlen(w), lent = strlen(t);
    int j = 0;
    for(int i = 0; i < lent; i++) {
        while(j && w[j]!=t[i]) j = f[j];
        if(w[j]==t[i]) j++;
        if(j==lenw) {
            cnt++;
            j = f[lenw];       // !!! key point.
        }
    }
    return cnt;
}


int main()
{
    int T;
    scanf("%d", &T);
    getchar();
    while(T--) {
        gets(w);
        gets(t);
        int res = match();
        printf("%d\n", res);
    }
    return 0;
}

POJ 3461 Oulipo,布布扣,bubuko.com

POJ 3461 Oulipo

原文：http://blog.csdn.net/achiberx/article/details/22994529