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>
#include <stdlib.h>

int main(){
    int n;
    scanf("%d", &n);
    char s[200];
    scanf("%s", s);
    char a[100], b[100];
    if (n%2 == 0){
        for(int i = 0; i < n; ++i){
            if (i < n/2){
                a[i] = s[i];
                //printf("AAA %c %c\n", a[i],s[i]);
            } else{
                b[i-(n/2)] = s[i];
                //printf("BBB %c %c\n", b[i-(n/2)],s[i]);
                //printf("%d %d\n", i-(n/2), i);
            }
        }
        a[n/2] = '\0';
        b[n/2] = '\0';

    }
    if (strcmp(a,b) == 0){
        printf("Yes\n");
    } else{
        printf("No\n");
    }
    //printf("%d\n",strcmp(a,b));
    return 0;
}