题解 | #从上往下打印二叉树#

```/* function TreeNode(x) {
    this.val = x;
    this.left = null;
    this.right = null;
} */
function TreeDepth(pRoot)
{
    // write code here
    //递归本质是DFS后序遍历，递归终止条件：该节点没有子节点了 返回值：当前节点深度
  if(pRoot == null) {return 0}
    let left = TreeDepth(pRoot.left)
    let right = TreeDepth(pRoot.right)
    return left>right?left+1:right+1
}
module.exports = {
    TreeDepth : TreeDepth
};