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
For each problem, you answer one multiple choice question about the data structure that solves it: what a trie node stores, what a union-find join counts, or which entry a cache removes. For a full explanation of the format, see the Speedrun overview.
This speedrun covers Union Find, Trie, and Data Structure Design. Before you start, complete those sections of the Advanced Data Structures chapter.