feat: add Same Tree

Author: dukeluo

README.md

@@ -62,6 +62,7 @@ Roadmap: https://neetcode.io/roadmap
 | 104 | [Maximum Depth of Binary Tree](https://leetcode.com/problems/maximum-depth-of-binary-tree/description/)                         | Easy       | [ts](./TypeScript/104.maximum-depth-of-binary-tree.ts)                                        | Trees            |
 | 543 | [Diameter of Binary Tree](https://leetcode.com/problems/diameter-of-binary-tree/description/)                                   | Easy       | [ts](./TypeScript/543.diameter-of-binary-tree.ts)                                             | Trees            |
 | 110 | [Balanced Binary Tree](https://leetcode.com/problems/diameter-of-binary-tree/description/)                                      | Easy       | [ts](./TypeScript/110.balanced-binary-tree.ts)                                                | Trees            |
+| 100 | [ Same Tree](https://leetcode.com/problems/same-tree/description/)                                                              | Easy       | [ts](./TypeScript/100.same-tree.ts)                                                           | Trees            |
 | 102 | [Binary Tree Level Order Traversal](https://leetcode.com/problems/binary-tree-level-order-traversal/)                           | Medium     | [ts](./TypeScript/102.binary-tree-level-order-traversal.ts)                                   | Trees            |
 | 46  | [Permutations](https://leetcode.com/problems/permutations/)                                                                     | Medium     | [ts](./TypeScript/46.permutations.ts)                                                         | Backtracking     |
 

TypeScript/100.same-tree.ts

@@ -0,0 +1,39 @@
+class TreeNode {
+  val: number;
+  left: TreeNode | null;
+  right: TreeNode | null;
+  constructor(val?: number, left?: TreeNode | null, right?: TreeNode | null) {
+    this.val = val === undefined ? 0 : val;
+    this.left = left === undefined ? null : left;
+    this.right = right === undefined ? null : right;
+  }
+}
+
+function isSameTree(p: TreeNode | null, q: TreeNode | null): boolean {
+  if (p === null && q === null) {
+    return true;
+  }
+
+  if (p === null || q === null) {
+    return false;
+  }
+
+  return (
+    p.val === q.val &&
+    isSameTree(p.left, q.left) &&
+    isSameTree(p.right, q.right)
+  );
+}
+
+const tree1 = new TreeNode(
+  3,
+  new TreeNode(9),
+  new TreeNode(20, new TreeNode(15), new TreeNode(7))
+);
+const tree2 = new TreeNode(
+  3,
+  new TreeNode(9),
+  new TreeNode(20, new TreeNode(15), new TreeNode(7))
+);
+
+console.log(isSameTree(tree1, tree2));