【BZOJ】【P1355】【Baltic2009】【Radio Transmission】【KMP】

传送门:http://www.lydsy.com/JudgeOnline/problem.php?id=1355

能自己想出来真是感人

不过为什么我的想法这么奇葩呢……

Code:

#include<bits/stdc++.h>
using namespace std;
const int maxn=2e6+5;
char s[maxn];
int next[maxn];
int n,nn,ans=maxn;
int c[maxn];
int main(){
	scanf("%d",&n);scanf("%s",s+1);nn=n;
	for(int i=2,j=0;i<=nn;i++){
		while(j&&s[i]!=s[j+1])j=next[j];
		next[i]=j+=s[i]==s[j+1];
		c[i]=i-next[i];
		if(i==n){
			copy(s+1,s+1+n,s+1+n-next[n]);
			nn=n+n-next[n];
		}
	}c[1]=1;
	cout<<*min_element(c+n,c+1+nn)<<endl;
	return 0;
}