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Courses

8 courses, in order. Start at 1, or jump to the one you need.

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Start with Arrays and Stacks

Each lesson links to the next one.

Start course 1
  1. 01

    Arrays and Stacks

    Scan, count, window, LIFO

    Arrays & Strings · Hashing · Two Pointers · Stack · Sliding Window

  2. 02

    Search

    Sorted space and lists

    Sorting · Binary Search · Linked List

  3. 03

    Recursion

    The gate

    Recursion · Trees · BST · Heap · Tries

  4. 04

    Graphs

    Decision trees and adjacency

    Backtracking · Graphs · Advanced Graphs

  5. 05

    Optimization

    Choose, then reuse

    Intervals + Greedy · 1D DP · 2D DP

  6. 06

    Design Method

    Requirements, numbers, interfaces

    Requirements · Estimation · Interfaces

  7. 07

    Building Blocks

    Cache, database, queue, partition

    Caching · Databases · Queues · Partitioning

  8. 08

    Worked Systems

    Shortener, limiter, feed, chat

    URL Shortener · Rate Limiter · News Feed · Chat