[Binary Tree

Author: zhaoguanchen

README.md

@@ -81,18 +81,28 @@ The project is divided into two parts: `structure` and `solution`.
 | No.  | Title                                                        | Difficulty | Solution                                                     | Idea                    |
 | ---- | ------------------------------------------------------------ | ---------- | ------------------------------------------------------------ | ----------------------- |
 | 94   | [Binary Tree Inorder Traversal](https://leetcode.com/problems/binary-tree-inorder-traversal/) | Easy       | [BinaryTreeInorderTraversal.java](src/leetcode/solution/tree/traversal/BinaryTreeInorderTraversal.java) | Recursion and Iteration |
+| 144  | [Binary Tree Preorder Traversal](https://leetcode.com/problems/binary-tree-preorder-traversal/) | Easy       | [BinaryTreePreorderTraversal.java](src/leetcode/solution/tree/traversal/BinaryTreePreorderTraversal.java) | Recursion and Iteration |
+| 145  | [Binary Tree Postorder Traversal](https://leetcode.com/problems/binary-tree-postorder-traversal/) | Easy       | [BinaryTreePostorderTraversal.java](src/leetcode/solution/tree/traversal/BinaryTreePostorderTraversal.java) | Recursion and Iteration |
 | 314  | [Binary Tree Vertical Order Traversal](https://leetcode.com/problems/binary-tree-vertical-order-traversal/) | Medium     | [BinaryTreeVerticalOrderTraversal.java](src/leetcode/solution/tree/traversal/BinaryTreeVerticalOrderTraversal.java) | Recursion and Iteration |
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+| 102  | [Binary Tree Level Order Traversal](https://leetcode.com/problems/binary-tree-level-order-traversal/) | Medium     | [BinaryTreeLevelOrderTraversal.java](src/leetcode/solution/tree/traversal/BinaryTreeLevelOrderTraversal.java) | BFS                     |
+
+**Construct**
+
+| No.  | Title | Difficulty | Solution | Idea |
+| ---- | ----- | ---------- | -------- | ---- |
+|      |       |            |          |      |
+|      |       |            |          |      |
+
+
+
+**Serialize and Deserialize**
+
+| No.  | Title | Difficulty | Solution | Idea |
+| ---- | ----- | ---------- | -------- | ---- |
+|      |       |            |          |      |
+|      |       |            |          |      |
+
+
 
 | No.  | Title                                                        | Difficulty | Solution                                                     | Idea                                                         |
 | ---- | ------------------------------------------------------------ | ---------- | ------------------------------------------------------------ | ------------------------------------------------------------ |

src/leetcode/solution/BFS/BinaryTreeLevelOrderTraversal.java

@@ -8,8 +8,6 @@
 
 /**
  * 94. Binary Tree Inorder Traversal
- * <p>
- * left - mid - right
  */
 public class BinaryTreeInorderTraversal {
 

src/leetcode/solution/tree/traversal/BinaryTreeInorderTraversal.java

@@ -6,8 +6,6 @@
 
 /**
  * 145. Binary Tree Postorder Traversal
- * <p>
- * left - right - mid
  */
 public class BinaryTreePostorderTraversal {
 

src/leetcode/solution/tree/traversal/BinaryTreePostorderTraversal.java

@@ -8,8 +8,6 @@
 
 /**
  * 144. Binary Tree Preorder Traversal
- * <p>
- * mid - left - right
  */
 public class BinaryTreePreorderTraversal {
 

src/leetcode/solution/tree/traversal/BinaryTreePreorderTraversal.java

@@ -1,18 +1,16 @@
-package leetcode.solution.BFS;
+package leetcode.solution.tree.traversal;
 
 import leetcode.structure.TreeNode;
 
 import java.util.*;
 
 /**
  * 103. Binary Tree Zigzag Level Order Traversal
- * Given the root of a binary tree, return the zigzag level order traversal of its nodes' values. (i.e., from left to right, then right to left for the next level and alternate between).
  */
 public class BinaryTreeZigzagLevelOrderTraversal {
 
     public static void main(String[] args) {
         Integer[] array = {3, 9, 20, null, null, 15, 7};
-//        Integer[] array = {1,2,3,4,5,6,7,8,9,10,11,12,13,14,15};
 
         TreeNode root = TreeNode.constructTree(array);
         System.out.println(zigzagLevelOrder(root));