Data Structures Algorithms Big O Common Structures

Practice 30 core DSA and Big-O concepts

What You'll Learn

Learn DSA fundamentals with free flashcards. Review Big-O notation, arrays, linked lists, trees, hash tables, sorting, and common algorithmic patterns.

Key Topics

  • Big-O runtime and space complexity essentials
  • Core data structures and common operations
  • Sorting and searching baseline concepts
  • Algorithmic patterns for interviews and coursework

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How to study this deck

Start with a quick skim of the questions, then launch study mode to flip cards until you can answer each prompt without hesitation. Revisit tricky cards using shuffle or reverse order, and schedule a follow-up review within 48 hours to reinforce retention.

Preview: Data Structures Algorithms Big O Common Structures

Question

Runtime that grows linearly with input size

Answer

O(n)

Question

Runtime that grows logarithmically

Answer

O(log n)

Question

Runtime for two nested loops over n elements

Answer

O(n^2)

Question

Average lookup time in a hash table

Answer

O(1) average

Question

Worst-case lookup in a balanced binary search tree

Answer

O(log n)

Question

Contiguous memory structure with index-based access

Answer

Array

Question

Dynamic structure of nodes pointing to next node

Answer

Linked list

Question

LIFO data structure

Answer

Stack

Question

FIFO data structure

Answer

Queue

Question

Tree where each node has at most two children

Answer

Binary tree

Question

Binary tree where left < root < right

Answer

Binary search tree

Question

Tree balanced by color rules to keep height near log n

Answer

Red-black tree

Question

Complete binary tree used for priority queues

Answer

Heap

Question

Graph representation using vertex neighbor lists

Answer

Adjacency list

Question

Graph traversal using a queue

Answer

Breadth-first search (BFS)

Question

Graph traversal using recursion or stack

Answer

Depth-first search (DFS)

Question

Algorithm for shortest paths with nonnegative edges

Answer

Dijkstra's algorithm

Question

Divide-and-conquer sorting with average O(n log n)

Answer

Quicksort

Question

Stable O(n log n) divide-and-conquer sorting

Answer

Mergesort

Question

Simple in-place sorting with repeated swaps

Answer

Bubble sort

Question

Search algorithm requiring sorted array and halving range

Answer

Binary search

Question

Technique storing solutions to overlapping subproblems

Answer

Dynamic programming

Question

Optimization strategy making locally best choices

Answer

Greedy algorithm

Question

Pattern using two indices moving through a sequence

Answer

Two pointers

Question

Pattern maintaining a moving subarray/subsequence window

Answer

Sliding window

Question

Backtracking commonly explores search space using

Answer

Recursion

Question

Collision resolution strategy using linked lists per bucket

Answer

Separate chaining

Question

Hash table strategy probing for next open slot

Answer

Open addressing

Question

Space complexity of storing n items in an array

Answer

O(n)

Question

Amortized append time for dynamic arrays

Answer

O(1) amortized