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>//strcmp を使用するためにインクルード

int main(){

    int N;
    scanf("%d\n",&N);

    char S[N+1],F[(N+1)/2],R[(N+1)/2];
    scanf("%s",S);

    for(int i=0;i<(N+1)/2;i++){

        F[i] = S[i];
    }

    for(int j=N-1;j>=(N+1)/2;j--){
        R[j - N/2] = S[j];
        printf("j=%d、文字は %c\n",j,R[j]);

    }

    //printf("元の文字は 「%s」 、 「%s」 と 「%s」\n",S,F,R);

    if(strcmp(F,R)==0 && N>1 && N%2 == 0) printf("Yes");//文字列比較、一致すると0出力?


    else printf("No");

    return 0;
}