POJ 2406 Power Strings KMP

题目链接

题意：问串S 最多能表示成多少个串的重复 输出重复的最大值

代码：

#include <cstdio>
#include <iostream>
#include <cstring>
using namespace std;
const int maxn = 1000000 + 5;
int NEXT[maxn];
char str[maxn];


int main(){
    while( scanf("%s",str) && str[0] != '.' ){
        int n = strlen(str);
        NEXT[0] = NEXT[1] = 0;
        for(int i = 1;i < n;++i){
            int j = NEXT[i];
            while( j && str[i] != str[j] ) j = NEXT[j];
            NEXT[i + 1] = str[i] == str[j] ? j + 1 : 0;
        }
        int ans;
        if(NEXT[n] == 0){
            ans = 1;
        }
        else{
            if(n % (n - NEXT[n]) == 0){
                ans = n / (n - NEXT[n]);
            }
            else ans = 1;
        }
        printf("%d\n",ans);
    }
    return 0;
}