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 9.2.1) (judge verdict: Wrong Answer)

#include<stdio.h>

int main(){
    int N=0;
    int i=0,j=0,X,k=0,sum=0;
    char s[200];
    char t[100];

    scanf("%d", &N);
    scanf("%s", s);
    for(;i<N/2;i++){
      //printf("%c\n", s[i]);
      if(s[i] != s[i+N/2]){
        k++;
      }
    }

    if(k != 0){
      printf("Yes\n");
    }else{
      printf("No\n");
    }

    return 0;
}