Problem:
Score : 200 points

Problem Statement

Given are a positive integer N and a string S of length N consisting of lowercase English letters.

Determine whether the string is a concatenation of two copies of some string.
That is, determine whether there is a string T such that S = T + T.

Constraints

1 \leq N \leq 100

S consists of lowercase English letters.

|S| = N

Input

Input is given from Standard Input in the following format:

N
S

Output

If S is a concatenation of two copies of some string, print Yes; otherwise, print No.

Sample Input 1

6
abcabc

Sample Output 1

Yes

Let T = abc, and S = T + T.

Sample Input 2

6
abcadc

Sample Output 2

No

Sample Input 3

1
z

Sample Output 3

No

Solution in C++14 (GCC 5.4.1) (judge verdict: Wrong Answer)

#include <iostream>
using namespace std;
int main(void){
    // Your code here!
    int N;
    string S;
    int count=0;
    cin>>N;
    cin>>S;
    
    for(int j=0;j<N/2;j++){
        if(S.at(j)==S.at(j+N/2)){
            count++;
        }
    }
    if(count==N/2){
        cout<<"Yes"<<endl;
    }
    else{
        cout<<"No"<<endl;
    }
    
    
}