二叉树递归 详解

public class TreeNode {
       int val = 0;
       TreeNode left = null;
       TreeNode right = null;
   
       public TreeNode(int val) {
           this.val = val;
   
       }
   
   }

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