Problems

Very easy · Geometry

Very easy · Priority Queue · Implementation

Hard · String suffix structures · Implementation

Very easy · Graphs

Very easy · Binary Search · Prefix Sums · Fenwick Tree

Very easy · Implementation

Very easy · Implementation

Very easy · Implementation · Strings

Very easy · Sorting · Brute force

Medium · Depth-first Search · Graphs

Hard · Dynamic programming · Greedy algorithms · Combinatorics

Hard · Dynamic programming

Hard · Graphs · Greedy algorithms · Constructive Algorithms

Easy · Strings · Brute force · Implementation

Medium · Greedy algorithms · Sorting

Medium · Constructive Algorithms · Geometry

Easy · Graphs · Depth-first Search · Breadth-first Search

Very easy · Math · Ternary search

Hard · Depth-first Search

Hard · Greedy algorithms · Sorting · Data Structures

Very easy · Graphs · Graph network flows

Very hard · Dynamic programming · Combinatorics · Number theory

Very hard · Graphs · Shortest paths · Math

Hard · Geometry · Math

Medium · Geometry