Maximum Depth of Binary Tree
very easy recursion
1 public class Solution { 2 public int maxDepth(TreeNode root) { 3 // IMPORTANT: Please reset any member data you declared, as 4 // the same Solution instance will be reused for each test case. 5 if(root == null) 6 return 0; 7 return Math.max(maxDepth(root.left), maxDepth(root.right)) + 1; 8 } 9 }