Binary Tree

Traversal

• DFS Traversal: (using recursion or iteration)
• Preorder traversal: mid → left → right
• Inorder traversal: left → mid → right
• Postorder traversal: left → right → mid

• BFS Traversal: (using iteration)
• Level traversal

• 144: Binary Tree Preorder Traversal

• 94: Binary Tree Inorder Traversal

• 145: Binary Tree Postorder Traversal

• Level Order Traversal
• 102: Binary Tree Level Order Traversal
• 107: Binary Tree Level Order Traversal II
• 199: Binary Tree Right Side View
• 637: Average of Levels in Binary Tree
• 429: N-ary Tree Level Order Traversal
• 515: Find Largest Value in Each Tree Row
• 116: Populating Next Right Pointers in Each Node
• 117: Populating Next Right Pointers in Each Node II
• 104: Maximum Depth of Binary Tree
• 111: Minimum Depth of Binary Tree
• 513: Find Bottom Left Tree Value

• 226: Invert Binary Tree

• 101: Symmetric Tree

• Traverse Backtracking
• 257: Binary Tree Paths
• 112: Path Sum

• Construct Binary Tree
• 654: Maximum Binary Tree
• 617: Merge Two Binary Trees

Binary Search Tree

• if the node’s left sub-tree is not Null, all values on the left sub-tree is smaller than the node’s value

• if the node’s right sub-tree is not Null, all values on the right sub-tree is bigger than the node’s value

• To get a sorted array from the BST, use Inorder Traversal

• BST → Ordered List (Inorder traversal) Or Inplace Operation
• 98: Validate Binary Search Tree
• 530: Minimum Absolute Difference in BST
• 501: Find Mode in Binary Search Tree

• 235: Lowest Common Ancestor of a Binary Search Tree

• 701: Insert into a Binary Search Tree

• 450: Delete Node in a BST

• 669: Trim a Binary Search Tree

• 108: Convert Sorted Array to Binary Search Tree

• 538: Convert BST to Greater Tree