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;
  scanf("%d",&n);
  char s[n],s1[n/2],s2[n/2];
  scanf("%s",s);
  if(n%2!=0)
  printf("No");
  else
  {
    int i;
    for(i=0;i<n/2;i++)
    {
    s1[i]=s[i];
    s2[i]=s[i+(n/2)];
    }
    if(strcmp(s1,s2)==0)
    printf("Yes");
    else
    printf("No");  
  }

  return 0;
}