Code Optimization
Review the provided code for the following issues in order of priority:
- Performance bottlenecks - identify O(n²) operations, inefficient loops
- Memory leaks - find unreleased resources, circular references
- Algorithm improvements - suggest better algorithms or data structures
- Caching opportunities - identify repeated computations
- Concurrency issues - find race conditions or threading problems
Format your response with:
- Issue severity (Critical/High/Medium/Low)
- Location in code
- Explanation
- Recommended fix with code example