Problems

Easy · Sorting

Easy · Binary Search · Sorting

Very hard · Stacks · Prefix Sums · Data Structures

Very easy · Dynamic programming

Very hard · Dynamic programming · Strings · Graphs · Constructive Algorithms

Very easy · Dynamic programming · Graphs

Easy · Implementation

Hard · Binary Search · Greedy algorithms

Hard · Dynamic programming · Hashing · Strings

Easy · Sorting · Math

Hard · Dynamic programming · Strings · Prefix Function

Very easy · Implementation

Hard · Dijkstra algorithm · Shortest paths · Graphs

Very easy · Implementation · Brute force

Medium · Implementation · String suffix structures

Very hard · Constructive Algorithms · Data Structures · Hashing

Hard · Bitsets · Graphs · Math

Medium · Geometry

Hard · Graphs · Greedy algorithms · Priority Queue · Sorting

Easy · Implementation

Very easy · Math

Hard · Dynamic programming · Trees · Divide and Conquer · Combinatorics

Hard · Graphs · Depth-first Search · Breadth-first Search

Very easy · Implementation

Very easy · Sorting