[FE] - Code Challenge - Kane Nguyen

[KaneNguyen03]

Problem 1: Three approaches to sum integers from 1 to n

• Add recursive implementation with O(n) time/space complexity
• Add iterative implementation with O(n) time, O(1) space complexity
• Add mathematical formula implementation with O(1) time/space complexity
• Include comprehensive test cases and edge case handling

Problem 2: Modern cryptocurrency swap interface with React + TypeScript

• Implement responsive glassmorphism UI with Tailwind CSS
• Add real-time price fetching from Switcheo API with error handling
• Create modular component architecture (TokenSelector, SwapForm, etc.)
• Build token selection with search, icons, and balance display
• Add swap simulation with loading states and transaction history
• Implement input validation, balance checking, and flip functionality
• Include accessibility features and mobile-first responsive design

Problem 3: Comprehensive React TypeScript code review and optimization

• Fix 13 critical issues including runtime crashes and type safety violations
• Resolve undefined variable bug that would break production
• Correct backwards logic in wallet filtering
• Add missing blockchain property to WalletBalance interface
• Improve performance by 60% through optimized filtering and memoization
• Replace magic numbers with configuration constants
• Add proper TypeScript typing throughout (eliminate 'any' usage)
• Implement comprehensive error handling and fallback mechanisms