leetcode

Maximum Depth of Binary Tree

Given a binary tree, find its maximum depth.

The maximum depth is the number of nodes along the longest path from the root node down to the farthest leaf node.

Solution1:

  public int maxDepth(TreeNode root) {    return maxDepth(root, 0);  }  private int maxDepth(TreeNode root, int max) {    if (root == null)      return max;    return Math.max(maxDepth(root.left, max + 1), maxDepth(root.right, max + 1));  }

Solution2:

better

  public int maxDepth(TreeNode root) {    if (root == null)      return 0;    return 1 + Math.max(maxDepth(root.left), maxDepth(root.right));  }