Glossary

Stack and Queue (data structures)

Stack and Queue are basic linear data structures with different access patterns. Stack: last in, first out (LIFO). Queue: first in, first out (FIFO).

Stack (LIFO)

push(A), push(B), push(C)
pop() → C
pop() → B

Uses: call stack, undo/redo, expression parsing, depth-first tree traversal (DFS).

enqueue(A), enqueue(B), enqueue(C)
dequeue() → A
dequeue() → B

Uses: task queues, breadth-first search (BFS), producer-consumer buffers.

Double-ended queue — add and remove from both ends. Combines capabilities of both stack and queue.