590. N叉树的后序遍历

590. N叉树的后序遍历

返回其后序遍历: [5,6,3,2,4,1].

栈是后进先出
同时 输出需要把最先出栈的元素放在队首

解题思路
代码
/**
 * Definition for a Node.
 * type Node struct {
 *     Val int
 *     Children []*Node
 * }
 */
func postorder(root *Node) []int {
    if root==nil{
        return nil
    }
    stack := make([]*Node,0)
    stack = append(stack,root)
    res := make([]int,0)
    for len(stack)>0{
        node := stack[len(stack)-1]
        stack = stack[:len(stack)-1]
        res = append([]int{node.Val},res...)
        for i:=0;i<len(node.Children);i++{
            stack = append(stack,node.Children[i])
        }
    }
    return res
}