Add solution for Challenge 19 by Johrespi

[Johrespi]

Challenge 19 Solution

Submitted by: @Johrespi
Challenge: Challenge 19

Description

This PR contains my solution for Challenge 19.

Changes

• Added solution file to challenge-19/submissions/Johrespi/solution-template.go

Testing

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

Thank you for reviewing my submission! 🚀

[coderabbitai]

Walkthrough

A new submission file is added containing four public slice utility functions for Go: FindMax, RemoveDuplicates, ReverseSlice, and FilterEven. Each function operates on integer slices with specific behaviors. A main function demonstrates their usage.

Changes

Cohort / File(s)	Change Summary
New solution file challenge-19/submissions/Johrespi/solution-template.go	Adds four exported slice utility functions: FindMax returns the maximum value in a slice; RemoveDuplicates removes duplicates while preserving order; ReverseSlice returns elements in reverse order; FilterEven returns only even numbers. Includes a main function demonstrating all utilities.

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~10 minutes

• Verify correctness of logic in each of the four utility functions (edge cases like empty slices, single elements)
• Check that RemoveDuplicates properly preserves original order
• Confirm ReverseSlice doesn't mutate the original slice
• Validate FilterEven correctly identifies and returns only even numbers

Possibly related PRs

• #601: Adds the same four exported slice utility functions (FindMax, RemoveDuplicates, ReverseSlice, FilterEven) with identical signatures in a different submission file
• #716: Adds the same four exported functions and demonstrating main in another challenge-19 solution-template.go submission

Pre-merge checks

✅ Passed checks (3 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title 'Add solution for Challenge 19 by Johrespi' accurately summarizes the main change—adding a solution file for Challenge 19.
Description check	✅ Passed	The description is directly related to the changeset, clearly explaining the Challenge 19 solution submission with details about the changes and testing.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.

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[coderabbitai]

Actionable comments posted: 0

🧹 Nitpick comments (4)

challenge-19/submissions/Johrespi/solution-template.go (4)

28-45: Remove TODO comment and run gofmt.

The function logic is correct and handles edge cases appropriately. However:

• Line 31 contains a TODO comment that should be removed since the function is implemented.
• Indentation is inconsistent (mixing spaces and tabs). Go convention strongly prefers tabs.

Run gofmt to automatically fix formatting:

#!/bin/bash
# Format the Go file according to Go conventions
gofmt -w challenge-19/submissions/Johrespi/solution-template.go

---

47-67: Remove TODO comment.

The implementation correctly removes duplicates while preserving order using a map-based approach with struct{}{} as the value type, which is a good Go practice for sets.

Apply this diff:

-	// TODO: Implement this function
-	

---

69-83: Remove TODO comment.

The implementation correctly reverses the slice by iterating backwards.

Apply this diff:

-	// TODO: Implement this function
-	

---

87-105: Remove TODO comment and simplify return logic.

The filtering logic is correct. However:

• Line 88 contains a TODO comment that should be removed.
• Lines 100-102 are redundant. If res is empty, it's already []int{}, so you can return it directly.

Apply this diff:

 	var res []int
 	for _, e := range numbers {
 	    if e % 2 == 0 {
 	        res = append(res, e)
 	    }
 	}
 	
-	if len(res) == 0 {
-	    return []int{}
-	}
-	
 	return res

Also remove the TODO comment:

-	// TODO: Implement this function

📜 Review details

Configuration used: CodeRabbit UI

Review profile: CHILL

Plan: Pro

📥 Commits

Reviewing files that changed from the base of the PR and between 4085963 and 59f49c1.

📒 Files selected for processing (1)

• challenge-19/submissions/Johrespi/solution-template.go (1 hunks)

🔇 Additional comments (1)

challenge-19/submissions/Johrespi/solution-template.go (1)

7-26: LGTM!

The demonstration code clearly exercises all four utility functions and provides useful output.