hdu 3746KMP的应用

其实很简单，只要对KMP的next数组的含义能理解的话，就没有问题了。

/*
 * hdu3746/win.cpp
 * Created on: 2012-8-2
 * Author    : ben
 */
#include <cstdio>
#include <cstdlib>
#include <cstring>
#include <cmath>
#include <ctime>
#include <iostream>
#include <algorithm>
#include <queue>
#include <set>
#include <map>
#include <stack>
#include <string>
#include <vector>
#include <deque>
#include <list>
#include <functional>
#include <numeric>
#include <cctype>
using namespace std;
const int MAX_LEN = 200010;
char pattern[MAX_LEN];
int next[MAX_LEN], parlen;
void getnext() {
    int i = 0, j = -1;
    next[0] = -1;
    while (i <= parlen) {
        if (j < 0 || pattern[i] == pattern[j]) {
            i++;
            j++;
            next[i] = j;
        } else {
            j = next[j];
        }
    }
}

int main() {
#ifndef ONLINE_JUDGE
    freopen("data.in", "r", stdin);
#endif
    int T, ans;
    scanf("%d", &T);
    while(T--) {
        scanf("%s", pattern);
        parlen = strlen(pattern);
        getnext();
        int ret = next[parlen];
        if(ret > parlen / 2) {
            int xhj = parlen - ret;
            ans = (xhj - parlen % xhj) % xhj;
        }else {
            ans = parlen - ret * 2;
        }
        printf("%d\n", ans);
    }
    return 0;
}