Codeforces 4A Watermelon Solution & Explanation

Difficulty : 800

Problem Description

One hot summer day Pete and his friend Billy decided to buy a watermelon. They chose the biggest and the ripest one, in their opinion. After that the watermelon was weighed, and the scales showed w kilos. They rushed home, dying of thirst, and decided to divide the berry, however they faced a hard problem.

Pete and Billy are great fans of even numbers, that’s why they want to divide the watermelon in such a way that each of the two parts weighs even number of kilos, at the same time it is not obligatory that the parts are equal. The boys are extremely tired and want to start their meal as soon as possible, that’s why you should help them and find out, if they can divide the watermelon in the way they want. For sure, each of them should get a part of positive weight.

Input

The first (and the only) input line contains integer number w (1 ≤ w ≤ 100) — the weight of the watermelon bought by the boys.

Output

Print YES, if the boys can divide the watermelon into two parts, each of them weighing even number of kilos; and NO in the opposite case.

Examples

Note

For example, the boys can divide the watermelon into two parts of 2 and 6 kilos respectively (another variant — two parts of 4 and 4 kilos).

Solution

First, let’s consider the constraints. Since each part’s weight must be a positive number, the smallest positive even number is 2.

Therefore, if the total weight of the watermelon is less than 4 kilos, it cannot meet the requirements, so we print “NO.”

Second, when we add two even numbers together, the result will always be another even number. Therefore, we can easily check this condition using the modulo operator (%), like so: “if (x % 2 === 0).“

C# Solution

Solution1

int x = int.Parse(Console.ReadLine());

if (x < 4)
{
    Console.WriteLine("NO");
}
else
{
    Console.WriteLine(x % 2 == 0 ? "YES" : "NO");
}

Console.ReadLine() will return a string object, so we need to convert to integer

Java Solution

Solution1

import java.util.Scanner;
 
public class Main {
    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        int x = scanner.nextInt();
 
        if (x < 4) {
            System.out.println("NO");
        } 
        else {
            System.out.println(x % 2 == 0 ? "YES" : "NO");
        }
    }
}

Python3 Solution

Solution1

x = int(input())

if x < 4:
    print("NO")
else:
    print("YES" if x % 2 == 0 else "NO")

Similar to C#, Python’s input() will return a string object

JavaScript Solution

Solution1

var x = readline();

if(x<4){
    print("NO");
}
else
{
    print(x%2===0?"YES":"NO");
}

Conclusion

This is my first Codeforces solution post. I tried Codeforces about a year ago, and I’ve noticed some differences compared to LeetCode. Codeforces is more competitive and offers a greater number of contests!!

But, LeetCode’s user interface is more user-friendly and straightforward, making it easier for many people to navigate and use.

🧡If my solution helps, that is my honor!

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✅If you got any problem about the explanation or you need other programming language solution, please feel free to let me know !!

The problem link : Problem – 4A – Codeforces

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