🗃️ Stacks & Queues
The "Cafeteria" Chapter
Imagine a stack of cafeteria trays - you can only take from the top! Or a checkout line - first person in line gets served first!
Easy
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Valid Parentheses
Do your brackets match up properly?
Easy
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Min Stack
A stack that can tell you the smallest item
Easy
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Implement Queue using Stacks
Build a queue when you only have stacks!
🎯 Brain Hack
Use a Stack when you need LIFO (Last In, First Out) - like undo buttons! Use a Queue when you need FIFO (First In, First Out) - like a waiting line!