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>
#include <string.h>
 
int main() {
    int a;
    scanf("%d", &a);
    char str1[256];
    char str2[256], str3[256];
    scanf("%s", str1);
    
    for (int i = 0; i < a/2; i++)
    {
        str2[i]=str1[i];
        str3[i]=str1[a/2 + i];
    }
    if(strcmp(str2,str3)== 0){
        printf("Yes");
    } else {
        printf("No");
    }
    return 0;
}