Problem:
Score : 200 points

Problem Statement

A string S of an odd length is said to be a strong palindrome if and only if all of the following conditions are satisfied:

S is a palindrome.

Let N be the length of S. The string formed by the 1-st through ((N-1)/2)-th characters of S is a palindrome.

The string consisting of the (N+3)/2-st through N-th characters of S is a palindrome.

Determine whether S is a strong palindrome.

Constraints

S consists of lowercase English letters.

The length of S is an odd number between 3 and 99 (inclusive).

Input

Input is given from Standard Input in the following format:

S

Output

If S is a strong palindrome, print Yes;
otherwise, print No.

Sample Input 1

akasaka

Sample Output 1

Yes

S is akasaka.

The string formed by the 1-st through the 3-rd characters is aka.

The string formed by the 5-th through the 7-th characters is aka.
All of these are palindromes, so S is a strong palindrome.

Sample Input 2

level

Sample Output 2

No

Sample Input 3

atcoder

Sample Output 3

No

Solution in C++ (GCC 9.2.1) (judge verdict: Wrong Answer)

#include<bits/stdc++.h>
#define mp make_pair
using namespace std;
typedef long long ll;
typedef long l;
typedef long long unsigned ull;



int main(){
    string s;
    cin>>s;
    int pos_start = (s.length()-1)/2;
    int pos_end = (s.length()+3)/2;
    int n = s.length();
    string a,b,c,d;
    for(int i=0,j=pos_start-1;i<pos_start,j>=0;i++,j--){
        a += s[i];
        b += s[j];
    }


    for(int i=pos_end-1,j=n-1;i<n,j>=pos_end-1;i++,j--){

        c += s[i];
        d += s[j];
    }

    if(a == b && c == d){
        cout<<"Yes";
    }
    else{
        cout<<"No";
    }

    return 0;

}