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 (GCC 5.4.1) (judge verdict: Accepted)

#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
#include <time.h>
#include <string.h>


int main()
{
  int len;
  scanf("%d", &len);
  char a[len+1];
  scanf("%s", a);

    int ans = 1;
    if(len%2!=0) ans=0;
    else {
      for(int i=0; i<len/2; i++){
        // printf("%c, %c\n", a[i], a[i+len/2]);
        if(a[i]!=a[i+len/2]) ans=0;
      }
    }

    if(ans==0) printf("No");
    else printf("Yes");

  return 0;
}