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>
#include <string.h>

int main(){
    int size, i, flag = 1;
    char string[101];
    scanf("%d ", &size);
    scanf("%s", string);
    if(size%2){
        flag = 0;
    }else{
        for(i=0; i<size/2; i++){
            if(string[i] != string[i+size/2]){
                flag = 0;
                break;
            }
        }
    }
    if(flag){
        printf("Yes");
    }else{
        printf("No");
    }
    return 0;
}