145:二叉树的后序遍历

LeetCode/src/main/java/leetcode/editor/cn/BinaryTreePostorderTraversal.java

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

LeetCode/src/main/java/leetcode/editor/cn/BinaryTreePostorderTraversal.md

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+<p>给定一个二叉树，返回它的 <em>后序&nbsp;</em>遍历。</p>
+
+<p><strong>示例:</strong></p>
+
+<pre><strong>输入:</strong> [1,null,2,3]  
+   1
+    \
+     2
+    /
+   3 
+
+<strong>输出:</strong> [3,2,1]</pre>
+
+<p><strong>进阶:</strong>&nbsp;递归算法很简单，你可以通过迭代算法完成吗？</p>
+<div><div>Related Topics</div><div><li>栈</li><li>树</li></div></div>\n<div><li>👍 564</li><li>👎 0</li></div>