HUST 1010 The Minimum Length

有一个字符串s，一次次的重写s，会得到一个新的字符串sssss.....,现在将这个字符串从中切去一部分得到一个字符串t

直接用n - next[n] 求循环节即可

#include <iostream>#include <cstring>#include <cstdio>#include <algorithm>#define rep(i, j, k) for(int i = j; i <= k; i++)#define maxn 1000009using namespace std;int n, Next[maxn];char s[maxn];void pre (){Next[0] = Next[1] = 0;rep (i, 1, n - 1){int j = Next[i];while (j && s[j] != s[i])j = Next[j];Next[i + 1] = s[i] == s[j] ? j + 1 : 0;}}int main (){while (scanf ("%s", s) == 1) {n = strlen (s);pre ();int len = n - Next[n];cout << len << endl;}return 0;}