/**
public class TreeNode {
int val = 0;
TreeNode left = null;
TreeNode right = null;
public TreeNode(int val) {
this.val = val;
}
}
*/
public class Solution { public int TreeDepth(TreeNode root) { if(root==null){ return 0; } //如果当前节点不为null，深度加1，再递归求出左右子树的深度，然后取最大值，即为树的深度 return Math.max(1+TreeDepth(root.left),1+TreeDepth(root.right)); } }