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 (Clang 3.8.0) (judge verdict: Wrong Answer)

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <stdbool.h>
#pragma warning(disable : 4996) //_CRT_SECURE_NO_WARNINGS

int main(void) {
	char s[100];
	int res = 0;
	scanf("%s", s);
	for (int i = 0, k = strlen(s) - 1;i <= k;i++, k--) {
		if(strncmp(s+i,s+k,1)==0) {
			res = 1;
		}
		else {
			res = 0;
			break;
		}
	}
	for (int i = 0, k = ((strlen(s) - 1)/2)-1;i <= k;i++, k--) {
		if (strncmp(s + i, s + k, 1) == 0) {
			res = 1;
		}
		else {
			res = 0;
			break;
		}
	}
	for (int i = ((strlen(s)+3)/2)-1, k = strlen(s) - 1;i <= k;i++, k--) {
		if (strncmp(s + i, s + k, 1) == 0) {
			res = 1;
		}
		else {
			res = 0;
			break;
		}
	}
	if (res == 1) {
		printf("Yes");
	}
	else {
		printf("No");
	}
	return 0;
}