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 N,M,i,j,k;
    char S[100],S_L[50],S_R[50];
    scanf("%d",&N);
    scanf("%s",S);
    for(i=0 ; i < 50 ; i++){
        S_L[i] = 0;
        S_R[i] = 0; 
    }
    if(N % 2 != 0){
        printf("No");
    }else{
        for(i = 0 ; i < N/2 ; i++){
            S_L[i]=S[i];
        }
        for(i = 0 ; i < N/2 ; i++){
            S_R[i] = S[i+N/2];
        }
        if(strcmp(S_L,S_R) == 0){
            printf("Yes");
        }else{
            printf("No");
        }
    }

    return 0;
}