Track 04

Algorithms & Data Structures

Arrays, trees, graphs, sorting, and dynamic programming. Classic computer science fundamentals with practical framing instead of pure whiteboard exercises.

0 / 8 solved

Module 01seeded3/4

Hash Maps

lookup, frequency counting, grouping, map-backed design

Problem 25·Hash Maps

Build a User Action Rate Limiter

easyStart →

Problem 36·Hash Maps

Group Duplicate Support Tickets

Fast Pathmedium

Problem 31·Hash Maps

Fix the Memory-Leaking LRU Cache

Capstonehard

Module 03seeded2/4

Two Pointers / Sliding Window

window invariants, pointer movement

Problem 37·Two Pointers / Sliding Window

Clean and Validate Usernames

easy

Problem 32·Two Pointers / Sliding Window

Extract the Smallest Matching Log Window

Capstonehard

Module 05seeded1/4

Binary Search

sorted search, rotated, boundary, search-on-answer

Problem 33·Binary Search

Split Video Jobs Across Workers

Capstonehard

Module 10seeded1/4

Tree

recursion, DFS, BFS, BST constraints, serialization

Problem 34·Tree

Serialize and Restore a Saved Navigation Tree

Capstonehard

Module 11seeded1/4

Heap / Priority Queue

top-k, streaming rank, merging feeds, scheduling

Problem 35·Heap / Priority Queue

Debug the Live Median Tracker

Capstonehard