Add solution for Challenge 2 by YESUBZERO

[YESUBZERO]

Challenge 2 Solution

Submitted by: @YESUBZERO
Challenge: Challenge 2

Description

This PR contains my solution for Challenge 2.

Changes

• Added solution file to challenge-2/submissions/YESUBZERO/solution-template.go

Testing

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

Thank you for reviewing my submission! 🚀

[coderabbitai]

Walkthrough

A new Go submission file is added to Challenge 2 that implements a string reversal function and CLI. The ReverseString function reverses input strings by iterating over runes, and the main function reads a line from stdin and prints the reversed output.

Changes

Cohort / File(s)	Change Summary
String Reversal CLI Implementation challenge-2/submissions/YESUBZERO/solution-template.go	Adds ReverseString(s string) string function that reverses strings by iterating over runes in reverse order; adds main function that reads input from stdin and prints reversed output; imports bufio, fmt, and os

Sequence Diagram

sequenceDiagram
    participant Main
    participant Stdin as Standard Input
    participant ReverseString
    participant Stdout as Standard Output

    Main->>Stdin: Read line
    Stdin-->>Main: Input string
    Main->>ReverseString: ReverseString(input)
    ReverseString->>ReverseString: Iterate runes in reverse
    ReverseString-->>Main: Reversed string
    Main->>Stdout: Print result

Loading

Estimated code review effort

🎯 1 (Trivial) | ⏱️ ~5 minutes

• Straightforward string reversal logic with rune iteration
• Simple CLI pattern with no complex control flow
• Single exported function with clear purpose

Possibly related PRs

• Add solution for Challenge 2 by AlexandrZlnov #620: Adds an exported ReverseString(s string) function in challenge-2/submissions/... with similar implementation structure
• Add solution for Challenge 2 by eksly #622: Adds an exported ReverseString function and CLI main in a different Challenge 2 submission implementing identical string-reversal functionality
• Add solution for Challenge 2 by macborowy #572: Adds a new Go submission for Challenge 2 with exported ReverseString and main that reads input and prints the reversed string

Pre-merge checks

✅ Passed checks (2 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title clearly describes the main change: adding a solution for Challenge 2 by a specific user (YESUBZERO), which directly corresponds to the changeset.
Description check	✅ Passed	The description is directly related to the changeset, providing context about the Challenge 2 solution submission, the file location, and testing claims.

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[coderabbitai]

Actionable comments posted: 1

🧹 Nitpick comments (2)

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

25-25: Remove the TODO comment.

The function is fully implemented, so the TODO comment should be removed to avoid confusion.

Apply this diff:

-	// TODO: Implement the function
 	var result string

---

24-32: Consider using strings.Builder for better performance.

The function correctly handles Unicode by iterating over runes. However, string concatenation in a loop creates a new string allocation on each iteration, resulting in O(n²) time complexity. For Go best practices, consider using strings.Builder or a []rune slice.

Here's a more efficient approach using a rune slice:

+import "strings"
+
 // ReverseString returns the reversed string of s.
 func ReverseString(s string) string {
-	var result string
-	
-	for _, char := range s {
-	    result = string(char) + result
-	}
-	return result
+	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)
 }

Alternatively, using strings.Builder:

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

📜 Review details

Configuration used: CodeRabbit UI

Review profile: CHILL

Plan: Pro

📥 Commits

Reviewing files that changed from the base of the PR and between 231bd24 and 6b862ca.

📒 Files selected for processing (1)

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

[coderabbitai]

⚠️ Potential issue | 🟡 Minor

Add error handling for scanner errors.

The scanner can fail for reasons other than EOF (e.g., I/O errors). Without checking scanner.Err(), these errors are silently ignored, which could confuse users when input fails unexpectedly.

Apply this diff to add proper error handling:

 func main() {
 	// Read input from standard input
 	scanner := bufio.NewScanner(os.Stdin)
 	if scanner.Scan() {
 		input := scanner.Text()
 
 		// Call the ReverseString function
 		output := ReverseString(input)
 
 		// Print the result
 		fmt.Println(output)
+	}
+	if err := scanner.Err(); err != nil {
+		fmt.Fprintf(os.Stderr, "Error reading input: %v\n", err)
+		os.Exit(1)
 	}
 }

Committable suggestion skipped: line range outside the PR's diff.

🤖 Prompt for AI Agents

In challenge-2/submissions/YESUBZERO/solution-template.go around lines 9 to 21,
the main function reads input with bufio.NewScanner but does not check for
scanner errors; after using scanner.Scan() add a call to scanner.Err(), and if
non-nil print a clear error to stderr (e.g., fmt.Fprintln(os.Stderr, "input
error:", err)) and exit with a non-zero status so I/O errors aren't silently
ignored.