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(void){
        char array[100];
        int a,i,flag = 0;
        int count = 0;

        scanf("%d",&a);
        scanf("%s",array);
        for(i = 0; i < a / 2 - 1;i++){
                if(array[i] == array[a / 2 + i]){
                        flag = 1;
                }else{
                        flag = 0;
                        break;
                } 
        }

        if(flag == 1){
                printf("Yes");
        }else{
                printf("No");
        }
        return 0;
}