题目链接:http://poj.org/problem?id=2406
解题思路:
水题。。。就是求模式串中的子串循环次数。
代码如下:
#include<iostream> #include<cstring> #include<cstdio> #include<string> #include<algorithm> using namespace std; #define N 1000010 char s[N]; int nextval[N]; int len; void getnext(const char *s) { int i = 0, j = -1; nextval[0] = -1; while(i != len) { if(j == -1 || s[i] == s[j]) nextval[++i] = ++j; else j = nextval[j]; } } int main() { int length, add; while(scanf("%s", s) && s[0] != '.') { len = strlen(s); getnext(s); length = len - nextval[len]; //循环节的长度 if(len != length && len % length == 0) //循环多次 printf("%d\n", len / length); else printf("1\n"); } return 0; }