99Tech Code Challenge Solutions

This repository contains my solutions for the 99Tech code challenges 1–3.

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Problem 1

• File: src/problem1/index.js
• Description: Implements three methods to sum numbers from 1 to n:
  1. Loop-based (sum_to_n_a)
  2. Recursive (sum_to_n_b)
  3. Array reduce (sum_to_n_c)
• Notes: It is assumed that only positive integers are accepted as input. Thus, input validation rejects zero or negative integers.

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Problem 2

• Folder: src/problem2/

• Description: A React + Vite project that implements a currency swap form.

  • Uses shadcn/ui components and tailwindcss.
  • Fully responsive for mobile and desktop.
  • Includes a swap confirmation dialog with loading and success toast.
  • Includes a simple toggle button for switching light/dark mode.

• How to run:

  cd src/problem2
  npm install
  npm run dev

Problem 3

• File: src/problem3/index.tsx
• Description: Refactored version of the provided messy React code.:
  • Contains in-line comments for specific fixes.
  • explanation.txt summarises all issues identified and solutions applied.
• Notes:
  • Standalone TypeScript file, assumes existence of useWalletBalances and usePrices hooks, as well as WalletRow component.
  • I created a minimal React project for Problem 3 to easily debug and visually verify the refactored component, even though the solution itself is a standalone TypeScript file.