Counting Factorizations

combinatorics, divide and conquer, dp, math, number theory

Graph Coloring (hard version)

brute force, combinatorics, divide and conquer, dp, fft, graphs

Graph Coloring (easy version)

combinatorics, dp, graphs

Serval and Toxel's Arrays

combinatorics, dp, implementation, math

Moving Dots

binary search, brute force, combinatorics, math, two pointers

Game on Axis

combinatorics, dfs and similar, dsu, graphs, implementation

Infinite Game

brute force, combinatorics, dp, games, probabilities

Wooden Spoon

combinatorics, dp

Bracket Insertion

combinatorics, dp, math, trees

Three Chairs

bitmasks, brute force, combinatorics, data structures, dp, number theory, sortings

Flexible String Revisit

combinatorics, dp, math, probabilities

Score of a Tree

bitmasks, combinatorics, dfs and similar, dp, math, probabilities, trees

Emordnilap

combinatorics, greedy, math

Another Wine Tasting Event

combinatorics, constructive algorithms, math, strings

Segment Covering

brute force, combinatorics, constructive algorithms, data structures, dp, trees

Game of Questions

bitmasks, combinatorics, dp, fft, math, probabilities

Dominoes

combinatorics, flows, graph matchings, greedy

Hossam and Combinatorics

combinatorics, math, sortings

Koxia and Sequence

bitmasks, combinatorics, dp, math, number theory

Koxia and Tree

combinatorics, dfs and similar, dp, dsu, math, probabilities, trees

Partial Sorting

combinatorics, math, number theory

Playoff

combinatorics, constructive algorithms, dp, greedy, math

Card Guessing

combinatorics, dp, probabilities

Doremy's Pegging Game

combinatorics, dp, math

Valid Bitonic Permutations

combinatorics, dp, implementation, math, number theory

Tree Sum

combinatorics, math, trees

Binary Strings are Fun

combinatorics, math

Anti-median (Hard Version)

combinatorics, dp, math

Carry Bit

combinatorics, math

Tick, Tock

combinatorics, dfs and similar, dsu, graphs

Doping

combinatorics, dp, math

Majority

combinatorics, dp, math, strings

Count GCD

combinatorics, math, number theory

Counting Arrays

combinatorics, dp, math, number theory

ConstructOR

bitmasks, chinese remainder theorem, combinatorics, constructive algorithms, math, number theory

List Generation

combinatorics, dp, math

Antifibonacci Cut

bitmasks, combinatorics, constructive algorithms, data structures, dp, hashing, math

Password

brute force, combinatorics, implementation, math

Conditional Mix

combinatorics, dp, math

Card Game

combinatorics, constructive algorithms, dp, games

Balance Addicts

combinatorics, dp, math, two pointers

Ela Goes Hiking

combinatorics, dp, math, probabilities

Meta-set

brute force, combinatorics, data structures, hashing, math

Bestie

brute force, combinatorics, constructive algorithms, implementation, math, number theory

Function Sum

brute force, combinatorics, dp, fft, math

Maximums and Minimums

combinatorics, data structures, divide and conquer, number theory

Cut Substrings

combinatorics, dp, hashing, strings, two pointers

Illumination

binary search, bitmasks, brute force, combinatorics, dp, math, two pointers

A Certain Magical Party

combinatorics, data structures, greedy, sortings

Almost Perfect

combinatorics, fft, math

Imitating the Key Tree

combinatorics, dsu, trees

Electrical Efficiency

combinatorics, data structures, dp, math, number theory, trees

Circular Mirror

binary search, combinatorics, geometry, math, two pointers

Madoka and The Corruption Scheme

combinatorics, constructive algorithms, greedy, math

Bags with Balls

combinatorics, dp, math, number theory

Monoblock

combinatorics, data structures, implementation, math

Lost Array

bitmasks, combinatorics, constructive algorithms, dp, math

LCM Sum (easy version)

binary search, brute force, combinatorics, math, number theory, two pointers

Partial Virtual Trees

combinatorics, dfs and similar, dp, math, trees

Mark and Professor Koro

binary search, bitmasks, brute force, combinatorics, data structures, greedy

Mark and Lightbulbs

combinatorics, constructive algorithms, greedy, math, sortings

Game of AI (hard version)

combinatorics, fft, math

Game of AI (easy version)

combinatorics, constructive algorithms, dp, fft, math

Points

combinatorics, data structures, implementation, math, matrices

The Third Problem

combinatorics, constructive algorithms, math

PermutationForces II

brute force, combinatorics, greedy, sortings, trees, two pointers

Coloring

brute force, combinatorics, constructive algorithms, dp, geometry, graphs, greedy, implementation, math

Maximum Product?

brute force, combinatorics, dp, greedy, implementation, math, two pointers

Placing Jinas

combinatorics, math

K-Set Tree

combinatorics, dfs and similar, dp, math, trees

Become Big For Me

combinatorics, constructive algorithms, greedy, math, number theory

Typical Party in Dorm

bitmasks, combinatorics, dp, strings

Infinite Replacement

combinatorics, implementation, strings

Dictionary

combinatorics, math

Power or XOR?

bitmasks, combinatorics, math, number theory

Lost Arithmetic Progression

combinatorics, math, number theory

Permutation Counting

brute force, combinatorics, dp, fft, math

Preorder

combinatorics, divide and conquer, dp, dsu, hashing, sortings, trees

Jee, You See?

bitmasks, combinatorics, dp

Centroid Probabilities

combinatorics, dp, fft, math

Fancy Stack

combinatorics, dp, implementation

Is it rated - 3

*special problem, combinatorics, dp, math

Drone Photo

combinatorics, math, sortings

Marin and Anti-coprime Permutation

combinatorics, math, number theory

Star MST

combinatorics, dp, graph matchings, math

Three Minimums

combinatorics, constructive algorithms, divide and conquer, dp, fft, math

Sum of Matchings

brute force, combinatorics, constructive algorithms, dfs and similar, graph matchings, greedy, math

Tyler and Strings

combinatorics, data structures, implementation

Weird Sum

combinatorics, data structures, geometry, math, matrices, sortings

Basis

combinatorics, fft, math, number theory

Expand the Path

brute force, combinatorics, data structures, implementation, math

Special Positions

combinatorics, divide and conquer, fft, math

Two Arrays

bitmasks, brute force, combinatorics, greedy, hashing, math, two pointers

Expected Components

combinatorics, math, number theory, probabilities

Game on Sum (Hard Version)

combinatorics, dp, games, math

Game on Sum (Easy Version)

combinatorics, dp, games, math

A Random Code Problem

combinatorics, dp, math, number theory, probabilities

Shuffle

combinatorics, math, two pointers

Subsequences Galore

bitmasks, combinatorics, dp

Keep XOR Low

bitmasks, combinatorics, data structures, divide and conquer, dp, math