Solving your first problem on Codeforces: Watermelon (4A) and the importance of structured programming

One of the first steps into competitive programming is solving simple but representative problems. A classic for beginners on Codeforces is the A. Watermelon problem, which tests your logic and your ability to translate simple conditions into code.

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📝 The problem: Watermelon

Summary:
Pete and Billy love sharing everything in even parts. They buy a watermelon weighing w kilos and want to split it into two parts, each of even weight (not necessarily equal), and both must have positive weight.
Is it possible?

• Input: An integer w (1 ≤ w ≤ 100), the weight of the watermelon.
• Output: “YES” if it can be split into two even parts, “NO” otherwise.

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🧠 Structured analysis of the problem

• When can a number be split into two even, positive parts?
  • The sum of two even numbers is always even.
  • For both to be > 0, w must be at least 4 (2 + 2).
  • Also, w must be even (if it’s odd, there’s no way to get two even parts).

Example cases:

• If w = 8: it can be split into 2+6 or 4+4 (both even, both > 0).
• If w = 2: you can only make 1+1 (but 1 is not even).
• If w = 5: not possible, it’s odd.

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💡 Logic and pseudocode

If w is even and w >= 4:
    Print "YES"
Else:
    Print "NO"

💻 Solution in C++

#include <iostream>
using namespace std;

int main() {
    int w;
    cin >> w;
    if (w % 2 == 0 && w >= 4)
        cout << "YES" << endl;
    else
        cout << "NO" << endl;
    return 0;
}

🐍 Solution in Python

w = int(input())
if w % 2 == 0 and w >= 4:
    print("YES")
else:
    print("NO")

🎯 Key lessons and best practices

State the problem in simple words before coding.

Structured programming helps you break the problem into small, clear conditions (in this case, using if statements).

This kind of exercise is perfect for sharpening your logic and problem-analysis skills.

Start with short problems and gradually increase the difficulty.

🚀 Conclusion

Solving your first problem on Codeforces may seem simple, but it’s a big step toward algorithmic logic and the discipline of competitive programming. The key is to understand the statement well, analyze the edge cases, and translate the logic into clean, readable code.

Do you have questions about this problem? Would you like me to solve other Codeforces classics? Leave a comment or reach out on social media! Keep practicing and you’ll see your skills grow day by day.

📝 References

• Watermelon problem on Codeforces
• Official Codeforces guide for beginners