Codeforces 1025A Doggo Recoloring（模拟）

 1 #include <set>
 2 #include <map>
 3 #include <queue>
 4 #include <deque>
 5 #include <stack>
 6 #include <cmath>
 7 #include <cstdio>
 8 #include <vector>
 9 #include <string>
10 #include <cstring>
11 #include <fstream>
12 #include <iostream>
13 #include <algorithm>
14 using namespace std;
15 
16 #define eps 1e-8
17 #define PI acos(-1.0)
18 #define INF 0x3f3f3f3f
19 #define FAST_IO ios::sync_with_stdio(false)
20 
21 typedef long long LL;
22 map <char,int> m;
23 
24 int main(){
25     FAST_IO;
26     int n;
27     string s;
28     cin>>n>>s;
29     if(n==1){
30         cout<<"Yes"<<endl;
31         return 0;
32     }
33     for(int i=0;i<n;i++){
34         m[s[i]]++;
35         if(m[s[i]]>=2){
36             cout<<"Yes"<<endl;
37             return 0;
38         }
39     }
40     cout<<"No"<<endl;
41     return 0;
42 }