Algorithm Explainer

Explain this algorithm clearly and completely: 1. **Purpose**: What problem does it solve? 2. **How It Works**: Step-by-step walkthrough 3. **Visual Example**: ASCII diagram or table showing execution 4. **Complexity Analysis**: Time and space complexity with explanation 5. **When to Use**: Best use cases and when to avoid 6. **Variations**: Common variations or optimizations 7. **Code**: Clean implementation with comments