题解 | #二叉树的后序遍历#

/*
 * function TreeNode(x) {
 *   this.val = x;
 *   this.left = null;
 *   this.right = null;
 * }
 */
/**
 * 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
 *
 * 
 * @param root TreeNode类 
 * @return int整型一维数组
 */
function postorderTraversal( root ) {
    // write code here
    let res = []
    function houSearch(node){
        if(node){
            houSearch(node.left)
            houSearch(node.right)
            res.push(node.val)
        }
    }
    houSearch(root)
    return res
}
module.exports = {
    postorderTraversal : postorderTraversal
};