Pseudocode to Implementation

Convert this pseudocode to {{language}} production code:

Pseudocode:
{{pseudocode}}

Constraints:
- Time complexity: {{time_complexity}}
- Space complexity: {{space_complexity}}
- Edge cases to handle: {{edge_cases}}
- Performance target: {{perf_target}}

Include: complete implementation, input validation, error handling, unit tests, and comments explaining algorithmic decisions.