Problems

Hard · Graph matchings · Greedy algorithms

Medium · Implementation

Easy · Math

Hard · Strings · Probabilities · Matrix · Number theory

Very easy · Brute force

Medium · Bitmasks · Brute force · Greedy algorithms · Sorting

Medium · Depth-first Search

Easy · Sorting

Easy · Brute force

Very easy · Math

Very easy · Graphs

Easy · Number theory · Implementation

Medium · Combinatorics · Number theory

Hard · Dynamic programming

Medium · Greedy algorithms · Constructive Algorithms · Sorting

Hard · Combinatorics · Matrix · Number theory

Medium · Geometry

Easy · Greedy algorithms

Very hard · 2-SAT · Graphs · Constructive Algorithms

Hard · Geometry · Convex Hull

Hard · Trees · Greedy algorithms · Depth-first Search

Easy · Implementation

Medium · Math · Matrix · Brute force

Medium · Bitmasks · Brute force

Very easy · Implementation