POD #2 – Compare the Triplets

It’s Monday again, which means it’s time for a new Problem of the Day. Today we’ll solve a well-known exercise called Compare the Triplets.

Problem Statement

Alice and Bob each created one problem for HackerRank. A reviewer rates the two challenges, awarding points on a scale from 1 to 100 for three categories:

• Problem clarity
• Originality
• Difficulty

The rating for Alice’s challenge is the triplet a = (a[0], a[1], a[2]), and the rating for Bob’s challenge is b = (b[0], b[1], b[2]). The task is to calculate their comparison points:

• If a[i] > b[i], then Alice is awarded 1 point.
• If a[i] < b[i], then Bob is awarded 1 point.
• If a[i] == b[i], then no points are awarded.

At the end, we return an array [alicePoints, bobPoints].

Example

a = [1, 2, 3]
b = [3, 2, 1]

• At index 0: a[0] < b[0] → Bob earns 1 point
• At index 1: a[1] == b[1] → no points
• At index 2: a[2] > b[2] → Alice earns 1 point

Result: [1, 1]

Try It Yourself

Before reading further, I strongly encourage you to try solving the exercise directly on HackerRank. Give it a shot, then come back here to compare your solution with mine. This practice of attempting first and reviewing later will sharpen your problem-solving skills much faster.

My Approach

The problem is straightforward: we just need to loop through the three elements, compare each value, and update the scores.

Since the input size is fixed (exactly 3 comparisons), both time and space complexity are constant:

• Time complexity: O(1)
• Space complexity: O(1)

Solution in C#

Here’s my implementation in C#:

public static List<int> CompareTriplets(List<int> a, List<int> b)
{
    int alicePoints = 0;
    int bobPoints = 0;

    for (int i = 0; i < 3; i++)
    {
        if (a[i] > b[i])
        {
            alicePoints++;
        }
        if (a[i] < b[i])
        {
            bobPoints++;
        }
    }

    return new List<int> { alicePoints, bobPoints };
}

Some Takeaways

• A clean solution doesn’t always mean a complex algorithm. Sometimes the simplest problems remind us to focus on clarity and correctness.
• Using two independent if statements keeps the logic straightforward and readable.
• It’s always good practice to test edge cases.

This post is part of my Problem of the Day series, where I solve one coding challenge each weekday and share my approach, solutions, and takeaways. See you in the next Problem of the Day!