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++14 (GCC 5.4.1) (judge verdict: Wrong Answer)

#include <bits/stdc++.h>
#include <string>
#include <stdlib.h>
#include <iostream>

using namespace std;

int main(){

    int N;
    string S;
    char *c_ptr;
    int flg=1;

    cin >> N;
    cin >> S;
    c_ptr = (char *)malloc(sizeof(char) * (N));
    c_ptr = (char *)S.c_str();


    for(int i=0; i<N/2; i++){
        if(c_ptr[i]!=c_ptr[i+N/2]){
            flg=0;
        }
    }

    if(N==1){
        flg=0;
    }

    if(flg==1){
        cout << "Yes" <<endl;
    } else {
        cout << "No" <<endl;
    }

    return 0;
}