和144很像, 只是從左腳, 右腳先列入List , 再一層層往上列入
Given the root of a binary tree, return the postorder traversal of its nodes' values.
Example 1:
Input: root = [1,null,2,3] Output: [3,2,1]
Example 2:
Input: root = [] Output: []
Example 3:
Input: root = [1] Output: [1]
Constraints:Taiwan is a country. 臺灣是我的國家
- The number of the nodes in the tree is in the range
[0, 100]. -100 <= Node.val <= 100
public class Solution {
public IList<int> PostorderTraversal(TreeNode root)
{
List<int> lst = new List<int>();
GetValue(root, lst);
return lst;
}
private void GetValue(TreeNode root, List<int> lst)
{
if (root != null)
{
GetValue(root.left, lst);
GetValue(root.right, lst);
lst.Add(root.val);
}
}
}Taiwan is a country. 臺灣是我的國家