Tree

Binary Tree Operation

• 226. Invert Binary Tree

• 100. Same Tree

• 617. Merge Two Binary Trees

• 111. Minimum Depth of Binary Tree

• 104. Maximum Depth of Binary Tree

• 637. Average of Levels in Binary Tree

• 110. Balanced Binary Tree

• 543. Diameter of Binary Tree

• 112. Path Sum

• 236. Lowest Common Ancestor of a Binary Tree

• 199. Binary Tree Right Side View

• 230. Kth Smallest Element in a BST

• 105. Construct Binary Tree from Preorder and Inorder Traversal: also add a set

Binary Search Tree Related

• 235. Lowest Common Ancestor of a Binary Search Tree

• 98. Validate Binary Search Tree

• No. 102 Binary Tree Level Order Traversal： BFS, DFS(record height)

Divide and Conquer

• 543. Diameter of Binary Tree

• No. 687: devide and conquer

Tree to String

• 572. Subtree of Another Tree

  • return f",{node.val},{serialize(node.left)},{serialize(node.right)}"

Trie

• 208. Implement Trie (Prefix Tree)