Add week 12 solutions: same-tree

Author: gitsunmin

same-tree/gitsunmin.ts

@@ -0,0 +1,24 @@
+/**
+ * https://leetcode.com/problems/same-tree/
+ * time complexity : O(n)
+ * space complexity : O(n)
+ */
+
+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;
+    if (p.val !== q.val) return false;
+
+    return isSameTree(p.left, q.left) && isSameTree(p.right, q.right);
+};