solution of maximum depth of binary tree

Author: grapefruit13

maximum-depth-of-binary-tree/grapefruit13.ts

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+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;
+  }
+}
+
+/**
+ * Time Complexity: O(n)
+ * Space Complexity: O(h)
+ */
+function maxDepth(root: TreeNode | null): number {
+  if (root === null) return 0;
+
+  let left = maxDepth(root.left);
+  let right = maxDepth(root.right);
+
+  return 1 + Math.max(left, right);
+}