HDU-1358 Period 字符串问题 KMP算法 求最小循环节

Posted 2020-12-27 tanglizi

题目链接：https://cn.vjudge.net/problem/HDU-1358

题意

给一个字符串，对下标大于2的元素，问有几个最小循环节

思路

对每个元素求一下minloop，模一下就好

提交过程

TLE	maxn没给够
AC

代码

#include <cstring>
#include <cstdio>
const int maxm=1e6+20;
char P[maxm];
int fail[maxm];
void getFail(int m){
    fail[0]=fail[1]=0;
    for (int i=1; i<m; i++){
        int j=fail[i];
        while (j && P[j]!=P[i]) j=fail[j];
        fail[i+1]=((P[i]==P[j])?j+1:0);
    }
}

int main(void){
    int len, kase=0;
    while (scanf("%d", &len)==1 && len){
        scanf("%s", P);
        getFail(len);

        printf("Test case #%d
", ++kase);
        for (int i=2; i<=len; i++){
            int maxloop=i-fail[i];
            if (maxloop!=i && i%maxloop==0) printf("%d %d
", i, i/maxloop);
        }printf("
");
    }

    return 0;
}

Time	Memory	Length	Lang	Submitted
78ms	6100kB	625	G++	2018-08-02 10:46:24