Add solution for Challenge 22 by n0l3r

[n0l3r]

Challenge 22 Solution

Submitted by: @n0l3r
Challenge: Challenge 22

Description

This PR contains my solution for Challenge 22.

Changes

• Added solution file to challenge-22/submissions/n0l3r/solution-template.go

Testing

• Solution passes all test cases
• Code follows Go best practices

Thank you for reviewing my submission! 🚀

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📥 Commits

Reviewing files that changed from the base of the PR and between 5727cc6 and ce9116a.

📒 Files selected for processing (1)

• challenge-22/submissions/n0l3r/solution-template.go

Walkthrough

A new Go solution file is added implementing a greedy coin-change algorithm with two exported functions: MinCoins computes the minimum coin count for a given amount, and CoinCombination returns a map of denomination-to-count pairs. A main function demonstrates usage with US coin denominations.

Changes

Cohort / File(s)	Summary
Coin-change greedy algorithm challenge-22/submissions/n0l3r/solution-template.go	New file with MinCoins(amount int, denominations []int) int and CoinCombination(amount int, denominations []int) map[int]int functions implementing greedy coin selection. Includes main function demonstrating usage with US denominations [1, 5, 10, 25, 50] and various test amounts. Returns -1 if amount cannot be formed.

Estimated code review effort

🎯 3 (Moderate) | ⏱️ ~20 minutes

Possibly related PRs

• RezaSi/go-interview-practice#654: Adds identical MinCoins and CoinCombination functions in a different submission file for Challenge 22.
• RezaSi/go-interview-practice#908: Implements nearly identical greedy coin-change functions for Challenge 22 in the same file structure.
• RezaSi/go-interview-practice#625: Adds the same two exported MinCoins and CoinCombination functions for Challenge 22 in a different submission file.

Pre-merge checks

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 66.67% which is insufficient. The required threshold is 80.00%.	You can run @coderabbitai generate docstrings to improve docstring coverage.

✅ Passed checks (2 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title accurately describes the main change: adding a solution for Challenge 22 submitted by n0l3r, which matches the changeset.
Description check	✅ Passed	The description is clearly related to the changeset, providing context about the Challenge 22 solution submission and the file added.

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Actionable comments posted: 2

🧹 Nitpick comments (3)

challenge-22/submissions/n0l3r/solution-template.go (3)

31-52: Document that greedy approach doesn't always produce minimum coins.

The greedy algorithm works for US coin denominations but doesn't guarantee the minimum number of coins for arbitrary denominations. For example, with denominations [1, 3, 4] and amount 6, greedy yields 3 coins (4+1+1) while optimal is 2 coins (3+3). Consider adding a comment noting this limitation.

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32-51: Inconsistent indentation detected.

Lines 33, 39, 42-44, and 48 use spaces instead of tabs, which is inconsistent with Go conventions. Run go fmt to normalize indentation.

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59-68: Inconsistent indentation detected.

Lines 61-62 and 65-67 use spaces instead of tabs. Run go fmt to normalize indentation.

📜 Review details

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro

📥 Commits

Reviewing files that changed from the base of the PR and between 669bf54 and 5727cc6.

📒 Files selected for processing (1)

• challenge-22/submissions/n0l3r/solution-template.go

🔇 Additional comments (1)

challenge-22/submissions/n0l3r/solution-template.go (1)

7-27: LGTM! Clear demonstration of the solution.

The main function provides a good demonstration with multiple test cases using standard US coin denominations.