What is a Stack? Explain LIFO.

Difficulty: 3/10

Memory Management, Call Stack, Undo/Redo Mechanisms

Stack and LIFO

A Stack is a linear data structure that follows the LIFO principle: Last In, First Out. The most recently inserted element is the first element removed. A stack typically exposes operations such as push, pop, and peek, all of which can be implemented in O(1) time.

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Insertion and deletion happen at the same end, called the top.
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LIFO means the newest element is processed first.
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Typical operations are O(1).
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Stacks can be implemented using arrays, dynamic arrays, or linked lists.
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Common uses include function calls, expression evaluation, undo operations, and backtracking.

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