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;

}