Trees: DSA Learning Path

Master binary trees, traversals, and recursive patterns, from your first DFS to hard interview problems

Every problem below runs in an in-browser editor with auto-judging and step-wise AI hints. Free, no signup needed to start.

Tree Foundations

10 essential concepts to understand before solving tree problems

• Trees Concepts Foundation

Tree Basics & Recursion

Your first tree recursions: measure a tree, then mirror it

• Maximum Depth of Binary Tree Easy
• Invert Binary Tree Easy

Tree Traversals: DFS & BFS

Master all four visit orders: preorder, inorder, postorder, and level order (your first BFS)

• Binary Tree Preorder Traversal Easy
• Binary Tree Inorder Traversal Easy
• Binary Tree Postorder Traversal Easy
• Binary Tree Level Order Traversal Medium

Comparing Structures

Walk two trees in lock-step: equality, then mirrors

• Same Tree Easy
• Symmetric Tree Easy

Paths & Measurements

Carry information down (path sum) and combine answers up (diameter)

• Path Sum Easy
• Diameter of Binary Tree Medium

Binary Search Trees

Use the BST ordering property: validate it, then exploit it

• Validate Binary Search Tree Medium
• Lowest Common Ancestor of a Binary Tree Medium

Advanced Tree Mastery

The hard ones: rebuild a tree from traversals, and the famous max path sum

• Construct Binary Tree from Preorder & Inorder Hard
• Binary Tree Maximum Path Sum Hard

All DSA learning paths