题解 | #二叉树的后序遍历#
二叉树的后序遍历
https://www.nowcoder.com/practice/1291064f4d5d4bdeaefbf0dd47d78541
import java.util.*;
//跟前序中序差不多，方法名以及顺序换一下就可以了
public class Solution {
List<Integer> list = new ArrayList<>();
public int[] postorderTraversal (TreeNode root) {
list = postOrder(root);
int[] res = new int[list.size()];
for (int i = 0; i < list.size(); i++) {
res[i] = list.get(i);
}
return res;
}
public List<Integer> postOrder(TreeNode root) {
if (root == null) return list;
postOrder(root.left);
postOrder(root.right);
list.add(root.val);
return list;
}
}
