Add solution for Challenge 17 by shansing

[shansing]

Challenge 17 Solution

Submitted by: @shansing
Challenge: Challenge 17

Description

This PR contains my solution for Challenge 17.

Changes

• Added solution file to challenge-17/submissions/shansing/solution-template.go

Testing

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

Thank you for reviewing my submission! 🚀

[coderabbitai]

Walkthrough

Adds a new Go solution file implementing a palindrome checker. The solution includes an exported IsPalindrome function that normalizes input by converting to lowercase and removing non-alphanumeric characters, then validates palindromes using two-pointer comparison from both ends.

Changes

Cohort / File(s)	Summary
Palindrome Checker Solution challenge-17/submissions/shansing/solution-template.go	New file adding IsPalindrome(s string) bool function that normalizes input via regex-based alphanumeric filtering and performs two-pointer palindrome validation. Includes main entry point for user interaction via standard input/output.

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~10 minutes

Possibly related PRs

• Add solution for Challenge 17 by Johrespi #731: Implements identical IsPalindrome function with same normalization and two-pointer checking logic for the same challenge.
• Add solution for Challenge 17 by wgasparin #801: Adds matching IsPalindrome implementation for Challenge 17 with equivalent cleaning and comparison approach across different submission files.
• Add solution for Challenge 17 by hudazaan #587: Implements the same exported IsPalindrome function signature with palindrome normalization and validation logic.

Poem

🐰 A palindrome checker hops into place,
Cleaning letters with regex grace,
Two pointers compare from end to start,
Racing toward truth with algorithmic heart! ✨

🚥 Pre-merge checks | ✅ 2 | ❌ 1

❌ Failed checks (1 warning)

Check name	Status	Explanation	Resolution
Docstring Coverage	⚠️ Warning	Docstring coverage is 50.00% which is insufficient. The required threshold is 80.00%.	Write docstrings for the functions missing them to satisfy the coverage threshold.

✅ Passed checks (2 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title 'Add solution for Challenge 17 by shansing' directly describes the main change: adding a solution file for Challenge 17, which matches the changeset.
Description check	✅ Passed	The description is related to the changeset, providing context about Challenge 17 submission, the file added, and testing claims, though details about the palindrome checker implementation are minimal.

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[coderabbitai]

Actionable comments posted: 1

🧹 Nitpick comments (2)

challenge-17/submissions/shansing/solution-template.go (2)

27-27: Simplify empty check: len(s) <= 0 → len(s) == 0.

len() never returns a negative value, so <= 0 is redundant.

-	if len(s) <= 0 {
+	if len(s) == 0 {

---

31-31: Compile regex once at package level to avoid repeated compilation.

regexp.MustCompile is called on every invocation of IsPalindrome, which adds unnecessary overhead. Hoisting it to a package-level variable compiles it once at init time.

Suggested fix

+var nonAlphanumericRegex = regexp.MustCompile("[^a-z0-9]+")
+
 // IsPalindrome checks if a string is a palindrome.
 // A palindrome reads the same backward as forward, ignoring case, spaces, and punctuation.
 func IsPalindrome(s string) bool {
 	if len(s) <= 0 {
 		return true
 	}
 	// 1. Clean the string (remove spaces, punctuation, and convert to lowercase)
-	cleaned := regexp.MustCompile("[^a-z0-9]+").ReplaceAllString(strings.ToLower(s), "")
+	cleaned := nonAlphanumericRegex.ReplaceAllString(strings.ToLower(s), "")
 	// 2. Check if the cleaned string is the same forwards and backwards

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ℹ️ Review info

Configuration used: Organization UI

Review profile: CHILL

Plan: Pro

📥 Commits

Reviewing files that changed from the base of the PR and between a7ac764 and 0f8202e.

📒 Files selected for processing (1)

• challenge-17/submissions/shansing/solution-template.go