99techteam · QuocVietHa08 · Mar 30, 2026 · Mar 30, 2026 · Mar 30, 2026
diff --git a/.DS_Store b/.DS_Store
diff --git a/readme.md b/readme.md
@@ -1,10 +1,15 @@
-# 99Tech Code Challenge #1 #
+# 🚀 Cool Coding Challenge
 
-Note that if you fork this repository, your responses may be publicly linked to this repo.  
-Please submit your application along with the solutions attached or linked.   
+A collection of interesting coding problems and their solutions.
 
-It is important that you minimally attempt the problems, even if you do not arrive at a working solution.
+## 📋 Challenges
+
+### 1️⃣ Sum of n Numbers
+**Problem:** [View Problem](src/problem1/problem.js)
+
+### 2️⃣ Swap Currency Form
+**Problem:** [View Live Link](https://code-challenge-xpzs.vercel.app/)
+
+### 3️⃣ Bug Detector
+**Problem:** [View Problem](src/problem3/solution.md)
 
-## Submission ##
-You can either provide a link to an online repository, attach the solution in your application, or whichever method you prefer.
-We're cool as long as we can view your solution without any pain.
diff --git a/src/.DS_Store b/src/.DS_Store
diff --git a/src/problem1/problem.js b/src/problem1/problem.js
@@ -0,0 +1,24 @@
+// Provide 3 unique implementations of the following function in JavaScript.
+// **Input**: `n` - any integer
+// *Assuming this input will always produce a result lesser than `Number.MAX_SAFE_INTEGER`*.
+// **Output**: `return` - summation to `n`, i.e. `sum_to_n(5) === 1 + 2 + 3 + 4 + 5 === 15`.
+
+var sum_to_n_a = function(n) {
+  let sum = 0;
+  for (let i = 1; i <= n; i++) {
+    sum += i;
+  }
+  return sum;
+};
+
+var sum_to_n_b = function(n) {
+  return n * (n + 1) / 2;
+};
+
+var sum_to_n_c = function(n) {
+  return Array.from({ length: n }, (_, i) => i + 1).reduce((acc, curr) => acc + curr, 0);
+};
+// ---- Test 
+console.log(sum_to_n_a(100));
+console.log(sum_to_n_b(100));
+console.log(sum_to_n_c(100));
diff --git a/src/problem2/.gitignore b/src/problem2/.gitignore
@@ -0,0 +1,24 @@
+# Logs
+logs
+*.log
+npm-debug.log*
+yarn-debug.log*
+yarn-error.log*
+pnpm-debug.log*
+lerna-debug.log*
+
+node_modules
+dist
+dist-ssr
+*.local
+
+# Editor directories and files
+.vscode/*
+!.vscode/extensions.json
+.idea
+.DS_Store
+*.suo
+*.ntvs*
+*.njsproj
+*.sln
+*.sw?
diff --git a/src/problem2/eslint.config.js b/src/problem2/eslint.config.js
@@ -0,0 +1,23 @@
+import js from '@eslint/js'
+import globals from 'globals'
+import reactHooks from 'eslint-plugin-react-hooks'
+import reactRefresh from 'eslint-plugin-react-refresh'
+import tseslint from 'typescript-eslint'
+import { defineConfig, globalIgnores } from 'eslint/config'
+
+export default defineConfig([
+  globalIgnores(['dist']),
+  {
+    files: ['**/*.{ts,tsx}'],
+    extends: [
+      js.configs.recommended,
+      tseslint.configs.recommended,
+      reactHooks.configs.flat.recommended,
+      reactRefresh.configs.vite,
+    ],
+    languageOptions: {
+      ecmaVersion: 2020,
+      globals: globals.browser,
+    },
+  },
+])
diff --git a/src/problem2/index.html b/src/problem2/index.html
@@ -1,26 +1,18 @@
-<html>
+<html lang="en">
 
 <head>
+  <meta charset="UTF-8" />
   <meta name="viewport" content="width=device-width, initial-scale=1">
+  <link rel="icon" type="image/svg+xml" href="/favicon.svg" />
   <title>Fancy Form</title>
-
-  <!-- You may add more stuff here -->
-  <link href="style.css" rel="stylesheet" />
 </head>
 
 <body>
 
   <!-- You may reorganise the whole HTML, as long as your form achieves the same effect. -->
-  <form onsubmit="return !1">
-    <h5>Swap</h5>
-    <label for="input-amount">Amount to send</label>
-    <input id="input-amount" />
-
-    <label for="output-amount">Amount to receive</label>
-    <input id="output-amount" />
-
-    <button>CONFIRM SWAP</button>
-  </form>
+  <!-- Original form replaced by React app mounted to #root -->
+  <div id="root"></div>
+  <script type="module" src="/src/main.tsx"></script>
   <script src="script.js"></script>
 </body>