You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
tech-interview-handbook/contents/algorithms/stack.md

3.3 KiB

id title description keywords sidebar_label toc_max_heading_level
stack Stack cheatsheet for coding interviews Stack study guide for coding interviews, including practice questions, techniques, time complexity, and recommended resources
stack coding interview study guide
stack tips for coding interviews
stack practice questions
stack useful techniques
stack time complexity
stack recommended study resources
Stack 2
<head> </head>

Introduction

A stack is an abstract data type that supports the operations push (insert a new element on the top of the stack) and pop (remove and return the most recently added element, the element at the top of the stack). As an abstract data type, stacks can be implemented using arrays or singly linked lists.

This behavior is commonly called LIFO (last in, first out). The name "stack" for this type of structure comes from the analogy to a set of physical items stacked on top of each other.

Stacks are an important way of supporting nested or recursive function calls and is used to implement depth-first search. Depth-first search can be implemented using recursion or a manual stack.

Learning resources

Implementations

Language API
C++ std::stack
Java java.util.Stack
Python Simulated using List
JavaScript Simulated using Array

Time complexity

Operation Big-O
Top/Peek O(1)
Push O(1)
Pop O(1)
isEmpty O(1)
Search O(n)

Corner cases

  • Empty stack. Popping from an empty stack
  • Stack with one item
  • Stack with two items

import AlgorithmCourses from '../_courses/AlgorithmCourses.md'