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

void reverse(char* S,char *rS) {
	int i = strlen(S)-1;
	for (int k=0;i >= 0;i--) {
		rS[k++] = S[i];
	}
	rS[strlen(S)] = '\0';
}

int main(void) {
	char S[100]; /*標準入力*/
	char rS[100]; /*標準入力反転*/
	int res = 0;
	scanf("%s", S);
	if (strlen(S) < 3 || strlen(S) > 99 || strlen(S)%2 ==0) {
		puts('No\n');
	}
	reverse(S, rS);
	//回文か判定
	if (strncmp(S, rS, strlen(S)) == 0) res = 1;
	//2つ目の条件
	for (int i = (strlen(S) - 1) / 2 - 1,k=0;i >= 0;i--) {
		rS[k++] = S[i];
	}
	if (strncmp(S, rS, ((strlen(S) - 1) / 2)) == 0) {
		res = 1;
	}
	else {
		res = 0;
	}
	//3つ目の条件
	for (int i =strlen(S)-1, k = 0;i >= ((strlen(S) + 3) / 2) - 1;i--) {
		rS[k++] = S[i];
	}
	if (strncmp(S + (((strlen(S) + 3) / 2) - 1), rS, ((strlen(S) - 1) / 2)) == 0) {
		res = 1;
	}
	else {
		res = 0;
	}
	if (res==1) {
		puts("Yes\n");
	}
	else {
		puts("No\n");
	}
	return 0;
}