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: Wrong Answer)

#include <stdio.h>

int main(){
    int N;
    scanf("%d", &N);
    char S[N];
    scanf("%s", S);

    int n = N + 1;

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

    return 0;
}