Stacks & Queues — Free DSA Tutorial
Learn Stacks & Queues in DSA with a free, beginner-friendly tutorial, examples and practice for Indian students on Syllab.in.
TL;DR: Learn Stacks & Queues in DSA with a free, beginner-friendly tutorial, examples and practice for Indian students on Syllab.in.
Written & reviewed by the Syllab.in Academic Team (CBSE/NCERT subject experts) · Updated
Stacks & Queues in DSA
A stack is Last-In-First-Out (LIFO) — like a stack of plates. You push onto the top and pop from the top, both O(1). Stacks power undo history, function calls (the call stack), expression evaluation and matching brackets.
A queue is First-In-First-Out (FIFO) — like a line at a shop. You enqueue at the back and dequeue from the front, both O(1) if you use the right structure (collections.deque, not a list). Queues power scheduling, buffering and breadth-first search.
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