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: Accepted)

#include <stdio.h>

int main (void)
{
        int n,c,i;

        scanf("%d",&n);

        char s[n];

        scanf("%s",s);

        if(n%2==1) printf("No");
        else{
        c=0;
        for(i=0;i<n/2;i++)
                if(s[i]==s[i+(n/2)]) c++;

        if(c==n/2) printf("Yes");
        else  printf("No");
        }
        return 0;
}