LESS SCROLLING. MORE SOLVING.

D4DSA Practice Path

One ordered path through every pattern a coding interview tests. Do Core for interview-ready coverage; add Plus for depth.

0 / 233 solved

233thoughtful problems

18patterns to understand

Core + Plusthe essentials, then the depth

Don’t just tick the box.
Learn why it works.

233 problems in view

Start here even if you have coded before. These eight teach you to reach for a hash map, a running best and a pair of pointers without thinking — the three reflexes every later step assumes you already have.

Problem	Difficulty	Track
Two Sum	easy	core
Best Time to Buy and Sell Stock	easy	core
Contains Duplicate	easy	core
Maximum Subarray	medium	core
Move Zeroes	easy	core
Remove Duplicates from Sorted Array	easy	core
Valid Anagram	easy	core
Plus One	easy	plus

D4DSA Practice Path

Foundations

Arrays & Hashing

Two Pointers

Sliding Window

Prefix Sums & Matrices

Binary Search

Stacks, Queues & Monotonic Stacks

Linked Lists

Recursion & Backtracking

Binary Trees

Binary Search Trees

Heaps & Top-K

Greedy & Intervals

Graphs

Dynamic Programming

Tries & String Algorithms

Bit Manipulation & Maths

Design & Data Structures