62 lines
1.5 KiB
Java
62 lines
1.5 KiB
Java
//给定一个二叉树，返回它的 后序 遍历。
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//
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// 示例:
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//
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// 输入: [1,null,2,3]
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// 1
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// \
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// 2
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// /
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// 3
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//
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//输出: [3,2,1]
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//
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// 进阶: 递归算法很简单，你可以通过迭代算法完成吗？
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// Related Topics 栈 树
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// 👍 564 👎 0
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package leetcode.editor.cn;
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import com.code.leet.entiy.TreeNode;
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import java.util.ArrayList;
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import java.util.List;
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//145:二叉树的后序遍历
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public class BinaryTreePostorderTraversal{
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public static void main(String[] args) {
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//测试代码
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Solution solution = new BinaryTreePostorderTraversal().new Solution();
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}
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//力扣代码
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//leetcode submit region begin(Prohibit modification and deletion)
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/**
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* Definition for a binary tree node.
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* public class TreeNode {
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* int val;
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* TreeNode left;
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* TreeNode right;
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* TreeNode() {}
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* TreeNode(int val) { this.val = val; }
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* TreeNode(int val, TreeNode left, TreeNode right) {
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* this.val = val;
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* this.left = left;
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* this.right = right;
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* }
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* }
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*/
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class Solution {
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public List<Integer> postorderTraversal(TreeNode root) {
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List<Integer> list = new ArrayList<>();
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if(root==null){
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return list;
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}
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list.addAll(postorderTraversal(root.left));
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list.addAll(postorderTraversal(root.right));
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list.add(root.val);
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return list;
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}
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}
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//leetcode submit region end(Prohibit modification and deletion)
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} |