DS & Algorithms
Master data structures, algorithms, and the exact coding patterns that top tech companies test for. This isn't theory for theory's sake — every concept here maps directly to what interviewers evaluate.
Your Learning Path
Four sections, one clear path. Master the concepts, learn the patterns, drill the essentials, then push beyond.
Concepts
16The foundational knowledge — data structures and algorithms explained with visual diagrams, complexity analysis, and real implementations.
ExplorePatterns
16The secret sauce that separates candidates who solve 500 problems randomly from those who solve 50 strategically. Reusable templates for every pattern.
ExploreEssential 75
75The 75 most frequently asked coding problems at top tech companies. Each with multiple approaches, key insights, and solutions in Python & JavaScript.
ExploreBeyond 75
75The next 75 most important problems after the Essential 75. Advanced patterns, tougher variations, and the problems that separate good from great.
ExploreFeatured Concepts
View all →Top Patterns
View all →Two Pointers
Medium difficulty
ExploreSliding Window
Medium difficulty
ExploreBinary Search
Medium difficulty
ExploreBFS / DFS on Trees
Medium difficulty
ExploreBFS / DFS on Graphs
Hard difficulty
ExploreBacktracking
Hard difficulty
ExploreDynamic Programming — 1D
Medium difficulty
ExploreDynamic Programming — 2D
Hard difficulty
Explore