Tree

我的學習路徑：

1. Basic traversal

   94->144->145

   程式碼總結

2. 用 Divide and Conquer 來判斷 tree 的性質

   110 - Balanced Binary Tree 98 - Validate Binary Search Tree 104 - Maximum Depth of Binary Tree

3. Path 系列

   112 - Path Sum 113 - Path Sum II 129 - Sum Root to Leaf Numbers

4. 資料結構轉換

   114 - Flatten Binary Tree to Linked List 105 - Construct Binary Tree from Preorder and Inorder Traversal 106 - Construct Binary Tree from Inorder and Postorder Traversal

5. 找到特定 node

   116 - Populating Next Right Pointers in Each Node 117 - Populating Next Right Pointers in Each Node II

6. 進階 traversal

   103 - Binary Tree Zigzag Level Order Traversal

7. 其他

   96 - Unique Binary Search Trees 95 - Unique Binary Search Trees II