最小表示法

#include<iostream>
#include<algorithm>
#include<vector>
#include<stack>
#include<queue>
#include<map>
#include<set>
#include<cstdio>
#include<cstring>
#include<cmath>
#include<ctime>
#define fuck(x) cout<<#x<<" = "<<x<<endl;
#define ls (t<<1)
#define rs ((t<<1)+1)
using namespace std;
typedef long long ll;
typedef unsigned long long ull;
const int maxn = 2000086;
const int inf = 2.1e9;
const ll Inf = 999999999999999999;
const int mod = 1000000007;
const double eps = 1e-6;
const double pi = acos(-1);
int n;
char s[maxn];

bool judge()
{
    for(int i=2;i<=n;i++){
        if(s[i]<s[1]){return false;}
        else if(s[i]==s[1]){
            int k=0;
            for(int j=1;j+i<=2*n;j++,k++){
                if(s[j]>s[i+j-1]){return false;}
                else if(s[j]<s[i+j-1]){break;}
            }
            i+=k;
        }
    }
    return true;
}

int main()
{
//    ios::sync_with_stdio(false);
//    freopen("in.txt","r",stdin);
    scanf("%d",&n);
    scanf("%s",s+1);
    for(int i=1;i<=n;i++){
        s[i+n]=s[i];
    }
    if(judge()){printf("Yes\n");}
    else printf("No\n");

    return 0;
}