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 (Clang 3.8.0) (judge verdict: Wrong Answer)

#include <stdio.h>
#include <string.h>

int main()
{
	int N, i, g = 0/*switch No*/;
	char a[100],b[100];
	scanf("%d", &N);
	scanf("%s", a);
	
	if (N % 2 == 1) {
		g++;
	}

	strcpy(b, a);
	
	for (i = 0; i <= N / 2 - 1; i++) {
		if (a[i] != b[i + (N / 2)]) {
			g++;
		}
	}

	if (g > 0) {
		printf("No\n");
	}
	else {
		printf("Yes\n");
	}
}