Home / By Topic

Questions by Topic

Practice problems organized by data structure and algorithm topics to focus your learning.

Data Structures

Linked List

3 questions

Master pointer manipulation and list traversal.

Reverse a Linked List Add Two Numbers Merge Two Sorted Lists

Strings

2 questions

Practice essential string manipulation patterns.

Merge Strings Alternately Longest Substring Without Repeating Characters

Trees

1 question

Explore hierarchical data structures and recursion.

Binary Tree Inorder Traversal

Arrays

1 question

Master array manipulation and indexing techniques.

Two Sum

Stacks & Queues

1 question

Learn LIFO and FIFO data structures.

Valid Parentheses

Hash Tables

Coming Soon

Master key-value pair storage and lookup.

🚧

Heaps

Coming Soon

Learn priority queues and heap operations.

🚧

Math

1 question

Master modular arithmetic and number manipulation.

Palindrome Number

Algorithms

Dynamic Programming

Coming Soon

Solve complex problems by breaking them down.

🚧

Linear Search

Coming Soon

Scan through elements to find a match.

🚧

Visual linear search guide coming soon!

Sorting Algorithms

Coming Soon

Visual comparisons: quicksort vs merge sort and more.

🚧

Sorting animations coming soon!

Binary Tree Traversal

Coming Soon

Inorder, preorder, postorder traversals visualized.

🚧

Traversal animations coming soon!

Two Pointers

Coming Soon

Efficiently solve problems with two moving pointers.

🚧

Sliding Window

1 question

Optimize problems with a moving window approach.

Longest Substring Without Repeating Characters

Binary Search

Coming Soon

Efficiently search in sorted data structures.

🚧

More binary search problems coming soon!

Graph Algorithms

Coming Soon

Master BFS, DFS, and graph traversal techniques.

🚧

Greedy

Coming Soon

Make locally optimal choices for global optimization.

🚧