🌳 Trees & Graphs
The "Family Tree & Subway Map" Chapter
Trees are like family trees - one root, branching down to children! Graphs are like subway maps - stations connected by lines, can go any direction!
Easy
→
Maximum Depth of Binary Tree
How tall is your family tree?
Easy
→
Invert Binary Tree
Flip the tree like a mirror!
Easy
→
Binary Tree Level Order
Visit tree level by level!
Medium
→
Number of Islands
Count islands in the ocean!
🎯 Brain Hack
Trees: DFS (Depth First Search) for recursion, BFS for level-order! Graphs: DFS for exploring deep, BFS for shortest path!