剑指offer38-二叉树的深度

/**
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;
        int nleft = TreeDepth(root.left);
        int nright = TreeDepth(root.right);
        return Math.max(nleft,nright)+1;
    }
}