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: Accepted)

#include <bits/stdc++.h>
using namespace std;
int main()
{
  int n,k,x=0;
  string s="";
  cin >> n >> s;
  if(n%2 == 0)
  {
    k = n/2;
    for(int t =0;t<k;t++)
    {
       if(s[t] == s[k+t]){++x;}
      
    }
    if(x==k){cout << "Yes" << endl;}
    else{cout << "No" <<endl;}
   }
  else{cout << "No"<<endl;}
}