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>
#include<string.h>
int main()
{
    int n, i, j, k;
    char string[101];
 
    scanf("%d", &n);
 
    scanf(" %[^\n]", string);
    if(n%2 != 0)
    {
        printf("No\n");
        return 0;
    }
    char copy1[n], copy2[n];
    for(i=0, j=0, k=0; string[i]!='\0' ; i++)
    {
        if(i<n/2)
        {
            copy1[j] = string[i];
            j++;
        }
 
        else
        {
            copy2[k] = string[i];
            k++;
        }
 
    }
    copy1[j] = '\0';
    copy2[k] = '\0';
 
    if(strcmp(copy1,copy2) == 0)
    {
        printf("Yes\n");
    }
    else
        printf("No\n");
 
    return 0;
 
}