Add solution for Challenge 21 by Kosench

[Kosench]

Challenge 21 Solution

Submitted by: @Kosench
Challenge: Challenge 21

Description

This PR contains my solution for Challenge 21.

Changes

• Added solution file to challenge-21/submissions/Kosench/solution-template.go

Testing

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

Thank you for reviewing my submission! 🚀

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No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro

Run ID: 819dd5b3-f494-462c-9b73-ac0e592217df

📥 Commits

Reviewing files that changed from the base of the PR and between f5e7ce5 and 4641d6d.

📒 Files selected for processing (1)

• challenge-21/submissions/Kosench/solution-template.go

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Walkthrough

Adds a new Go solution file for Challenge 21 implementing iterative binary search, recursive binary search, and an insertion-position search function, along with a main function that demonstrates and prints results from each.

Changes

Binary Search Solution

Layer / File(s)	Summary
Binary search implementations and demo challenge-21/submissions/Kosench/solution-template.go	Adds BinarySearch, BinarySearchRecursive, and FindInsertPosition functions along with a main function that tests each against a sample sorted array.

Estimated code review effort: 1 (Trivial) | ~5 minutes

Possibly related PRs

• RezaSi/go-interview-practice#586: Adds the same three functions (BinarySearch, BinarySearchRecursive, FindInsertPosition) in a Challenge 21 solution-template.go with matching behavior.
• RezaSi/go-interview-practice#626: Adds the same binary-search utility functions with identical signatures and behavior in a separate submission.
• RezaSi/go-interview-practice#1554: Adds the same three Challenge 21 utilities with matching binary-search and insertion-position logic in a different submission file.

Poem

Hop, hop, through arrays sorted neat,
Left and right bounds, midpoint feet 🐰
Found or not, insert with grace,
Recursion bounces round the place,
A rabbit's search, both quick and sweet!

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title accurately summarizes the main change: adding Kosench's Challenge 21 solution.
Description check	✅ Passed	The description clearly matches the change by describing the Challenge 21 solution file and testing claims.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.

Warning

There were issues while running some tools. Please review the errors and either fix the tool's configuration or disable the tool if it's a critical failure.

🔧 golangci-lint (2.12.2)

level=error msg="[linters_context] typechecking error: pattern ./...: directory prefix . does not contain main module or its selected dependencies"

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[github-actions]

🎉 Auto-merged!

This PR was automatically merged after 2 days with all checks passing.

Thank you for your contribution, @Kosench!

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