You are on level: Student
Overview
Quick DSA Review
Basic Algorithms
Sorted Array
Implicitly Sorted Array
Advanced
Speedrun
Core Concepts
Same Direction
Opposite Direction
Sliding Window
Prefix Sum
Cycle Finding
Decision Making
Introduction
DFS on Tree
Binary Search Tree
Combinatorial Search
Additional States
Aggregation and Memoization
Additional Practices
Speedrun
Introduction
Vanilla BFS
Matrix as Graph
Implicit Graph
Directed Graph / Topological Sort
Weighted Graph
Minimum Spanning Tree
Speedrun
Introduction
Top K
Moving Best
Multiple Heaps
Speedrun
Introduction
Constant Transition
Grid
Dual-Sequence
Non-constant Transition
Knapsack, Weight-Only
Knapsack, Weight+Value
Topological Sort
Additional Practices
Disjoint Set Union | Union Find
Data Structure Design
Segment Tree
Speedrun
Interval
Monotonic Stack
Tree Traversal without Recursion
Speedrun
Amazon OA
Microsoft OA
Google OA
The other speedruns each cover one chapter, so you know the technique before you read the problem. This speedrun mixes problems from every chapter in no fixed order. For each problem, first decide which technique solves it, and then answer the question. For a full explanation of the format, see the Speedrun overview.
Every question here also appears in a chapter speedrun. Do this one after you finish the course, or before an interview, to review all the patterns at once.