99techteam · ngochieu276 · Feb 10, 2026 · Feb 10, 2026 · Feb 10, 2026 · Feb 10, 2026
diff --git a/src/problem1/index.ts b/src/problem1/index.ts
@@ -0,0 +1,21 @@
+const sum_to_n_a = function (n: number) {
+  if (n <= 0) return 0;
+  n = Math.floor(n);
+  let sum = 0;
+  for (let i = 1; i <= n; i++) {
+    sum += i;
+  }
+  return sum;
+};
+
+const sum_to_n_b = function (n: number) {
+  if (n <= 0) return 0;
+  n = Math.floor(n);
+  return (n * (n + 1)) / 2;
+};
+
+const sum_to_n_c = function (n: number) {
+  if (n <= 0) return 0;
+  n = Math.floor(n);
+  return Array.from({ length: n }, (_, i) => i + 1).reduce((acc, v) => acc + v, 0);
+};
diff --git a/src/problem2/.gitignore b/src/problem2/.gitignore
@@ -0,0 +1,21 @@
+node_modules/
+dist/
+coverage/
+.vscode/
+.idea/
+.eslintcache
+*.tsbuildinfo
+.DS_Store
+Thumbs.db
+*.log
+npm-debug.log*
+yarn-debug.log*
+pnpm-debug.log*
+lerna-debug.log*
+.env
+.env.local
+.env.development.local
+.env.production.local
+.env.test.local
+*.swp
+*.swo
diff --git a/src/problem2/index.html b/src/problem2/index.html
@@ -1,27 +1,13 @@
-<html>
-
-<head>
-  <meta name="viewport" content="width=device-width, initial-scale=1">
-  <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>
-  <script src="script.js"></script>
-</body>
-
+<!doctype html>
+<html lang="en">
+  <head>
+    <meta charset="UTF-8" />
+    <link rel="icon" type="image/svg+xml" href="/vite.svg" />
+    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
+    <title>Coin Swap</title>
+  </head>
+  <body>
+    <div id="root"></div>
+    <script type="module" src="/src/main.tsx"></script>
+  </body>
 </html>