binary tree - dfs recu O(n) O(n)

Author: lukeist

leetcode-104-maximumDepthOfBinaryTree.js

@@ -0,0 +1,20 @@
+/**
+ * Definition for a binary tree node.
+ * function TreeNode(val, left, right) {
+ *     this.val = (val===undefined ? 0 : val)
+ *     this.left = (left===undefined ? null : left)
+ *     this.right = (right===undefined ? null : right)
+ * }
+ */
+/**
+ * @param {TreeNode} root
+ * @return {number}
+ */
+
+// p: root of bi tree
+// r: num
+
+var maxDepth = function (root) {
+  if (!root) return 0;
+  return 1 + Math.max(maxDepth(root.left), maxDepth(root.right));
+};