Problems

Very easy · Disjoint set union

Very easy · Math · Brute force

Easy · Number theory · Math

Easy · Optimization

Very easy · Number theory

Easy · Number theory

Medium · Number theory

Very easy · Number theory

Very easy · Brute force

Easy · Greedy algorithms

Medium · Geometry · Implementation

Medium · Binary Search

Very easy · Implementation

Very easy · Dynamic programming

Easy · Implementation

Medium · Greedy algorithms · Disjoint set union · Sorting · Geometry

Medium · Shortest paths · Dijkstra algorithm

Very easy · Shortest paths

Very easy · Graphs

Very hard · Depth-first Search · Expression parsing

Medium · Graphs

Easy · String suffix structures

Hard · Implementation

Easy · Geometry

Easy · Graphs