Add solution for Challenge 2 by inok94

[inok94]

Challenge 2 Solution

Submitted by: @inok94
Challenge: Challenge 2

Description

This PR contains my solution for Challenge 2.

Changes

• Added solution file to challenge-2/submissions/inok94/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 for Challenge 2 that implements a string reversal solution. The program reads a single line from standard input, reverses it using a ReverseString function with strings.Builder, and outputs the result.

Changes

Cohort / File(s)	Summary
Challenge 2 Submission challenge-2/submissions/inok94/solution-template.go	Adds a complete Go program with a ReverseString function that reverses strings by iterating from end to start via strings.Builder, and a main function that reads input from stdin and prints the reversed output

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~8 minutes

• Review the ReverseString implementation for correctness with edge cases (empty strings, multi-byte characters)
• Verify the main function properly handles input from stdin and outputs the correct result
• Check that the strings.Builder approach is efficiently sized and used correctly

Possibly related PRs

• Add solution for Challenge 2 by Xxploiter #639: Adds the same ReverseString(s string) string function in challenge-2's solution-template.go with a byte/strings.Builder implementation.
• Add solution for Challenge 2 by ansmonjol #752: Implements a ReverseString function for Challenge 2 using bytes with strings.Builder, similar algorithmic approach.
• Add solution for Challenge 2 by AlexandrZlnov #620: Adds a ReverseString function and main that reads input and prints the reversed string for Challenge 2.

Pre-merge checks

❌ 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%.	You can run @coderabbitai generate docstrings to improve docstring coverage.

✅ Passed checks (2 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title directly and clearly describes the main change: adding a solution for Challenge 2 by a specific contributor (inok94).
Description check	✅ Passed	The description is directly related to the changeset, clearly explaining that it contains a Challenge 2 solution submission with specific file changes and testing confirmation.

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[coderabbitai]

Actionable comments posted: 1

🧹 Nitpick comments (2)

challenge-2/submissions/inok94/solution-template.go (2)

10-22: Consider adding error handling for scanner errors.

While the logic correctly handles the single-line input case, consider checking scanner.Err() after the scan to catch potential I/O errors. This would make the solution more robust.

You could add after line 21:

	if err := scanner.Err(); err != nil {
		fmt.Fprintf(os.Stderr, "Error reading input: %v\n", err)
		os.Exit(1)
	}

---

29-29: Inconsistent indentation - run gofmt.

This line appears to use spaces for indentation instead of tabs. Run gofmt -w solution-template.go to automatically fix formatting according to Go conventions.

📜 Review details

Configuration used: CodeRabbit UI

Review profile: CHILL

Plan: Pro

📥 Commits

Reviewing files that changed from the base of the PR and between ca8ea29 and 7e001d7.

📒 Files selected for processing (1)

• challenge-2/submissions/inok94/solution-template.go (1 hunks)

🔇 Additional comments (1)

challenge-2/submissions/inok94/solution-template.go (1)

1-8: LGTM!

Package declaration and imports are appropriate for this string reversal program.

[coderabbitai]

⚠️ Potential issue | 🟠 Major

Critical: Byte-level reversal breaks UTF-8 multi-byte characters.

The current implementation uses s[i] which indexes individual bytes, not Unicode code points (runes). This will corrupt multi-byte UTF-8 characters like emoji, Chinese characters, etc.

For example:

• Input: "Hello世界" (where 世 and 界 are 3 bytes each)
• Expected: "界世olleH"
• Actual: Corrupted UTF-8 byte sequence

Apply this diff to correctly handle UTF-8:

 func ReverseString(s string) string {
-	builder := strings.Builder{}
-	builder.Grow(len(s))
-	for i := len(s) - 1; i >= 0; i-- {
-	    builder.WriteByte(s[i])
-	}
-	
-	return builder.String()
+	runes := []rune(s)
+	for i, j := 0, len(runes)-1; i < j; i, j = i+1, j-1 {
+		runes[i], runes[j] = runes[j], runes[i]
+	}
+	return string(runes)
 }

This approach converts the string to a rune slice, reverses in-place by swapping, and converts back to a string.

🤖 Prompt for AI Agents

In challenge-2/submissions/inok94/solution-template.go around lines 25 to 33,
the function reverses bytes (using s[i]) which corrupts multi-byte UTF-8
characters; fix by converting the string to a []rune, reverse the rune slice
in-place by swapping runes from ends toward the center, then convert the rune
slice back to a string and return it so UTF-8 characters remain intact.