← Tree Traversal

Micro-Drill #62 — Preorder traversal

Tree Traversal Target: 10s

Preorder visits root first. Used for serialization and tree construction.

def preorder(node):
    if not node: return
    visit(node)
    preorder(node.left)
    preorder(node.right)

Type it from memory. Go.

Practice Problems

• 144. Binary Tree Preorder Traversal
• 105. Construct Binary Tree from Preorder and Inorder Traversal

Related Coding Drills

• Drill #38 — Preorder traversal Easy
• Drill #37 — Inorder traversal Easy
• Drill #39 — Level-order traversal (BFS) Medium