Description

Input

Output

Sample Input

Sample Output

HINT

對於樣例,我們可以利用"abc"不斷自我連接得到"abcabcabc",讀入的cabcabca,是它的子串

Source

當 n%(n-next[n])==0 的時候 n-next[n] 就是當前字符串的最小循環節qwq 這性質好像laj在之前某篇博文裏證明過qwq

 1 #include "bits/stdc++.h"
 2 using namespace std;
 3 typedef long long LL;
 4 const int MAX=1e6+5;
 5 char s[MAX];
 6 int len,next[MAX];
 7 void get_next(){
 
 8     int i,j;
 9     j=next[0]=-1;i=0;
10     while (i<=len){
11         if (j==-1 || s[i]==s[j]) next[++i]=++j;
12         else j=next[j];
13     }
14 }
15 int main(){
16     freopen ("radio.in","r",stdin);freopen ("radio.out","w",stdout);
17     int i,j;
18     scanf("%d\n%s",&len,s);
19     get_next();
 
20     printf("%d",len-next[len]);
21     return 0;
22 }

BZOJ-1355: [Baltic2009]Radio Transmission (傻逼KMP)