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>

int main(){

    int N = 0;
    int count = 0;

    scanf("%d", &N);

    char S[N];

    scanf("%s", S);

    if(N % 2 == 0){
        for(int i = 0; i < N / 2; i++){
            if(S[i] == S[i + N / 2]){
                count++;
            } else {
                printf("No\n");
                break;
            }
        }
    } else {
        printf("No\n");
    }
    if(count == N / 2 && N != 1){
       printf("Yes\n"); 
    }

    return 0;
}