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 Java8 (OpenJDK 1.8.0) (judge verdict: Accepted)

import java.util.*;
public class Main{
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        int n = sc.nextInt();
        String s = sc.next();
        int half = s.length()/2;
        int cnt=0;

        if(s.length()==1){
            cnt++;
        }
        if(s.length()%2==1){
            cnt++;
        }

        for(int i =0; i<half;i++){
            if(s.charAt(i)!=s.charAt(i+half)){
                cnt++;
            }
        }

        if(cnt==0){
            System.out.println("Yes");
        }else{
            System.out.println("No");
        }

     
    }
}