Playoff

combinatorics, constructive algorithms, dp, greedy, math

Guess the String

constructive algorithms, interactive, probabilities

Watch the Videos

binary search, constructive algorithms, two pointers

Doremy's Experimental Tree

brute force, constructive algorithms, dfs and similar, dsu, sortings, trees

Another Array Problem

brute force, constructive algorithms, greedy

Absolute Maximization

bitmasks, constructive algorithms, greedy, math

Unequal Adjacent Elements

constructive algorithms, sortings

GCD Queries

constructive algorithms, interactive, number theory

Make Array Good

constructive algorithms, implementation, number theory, sortings

Make It Connected

binary search, brute force, constructive algorithms, dsu, graphs, greedy, matrices, trees, two pointers

Set Construction

constructive algorithms, dfs and similar, graphs, greedy

Elimination of a Ring

constructive algorithms, greedy, implementation

Two Permutations

brute force, constructive algorithms

Restore the Permutation

binary search, constructive algorithms, data structures, greedy, math

Decent Division

constructive algorithms, data structures

Range = √Sum

binary search, brute force, constructive algorithms, math, two pointers

XOR = Average

constructive algorithms

SSeeeeiinngg DDoouubbllee

constructive algorithms, strings

Kevin and Permutation

constructive algorithms, greedy, math

The Beach

constructive algorithms, dfs and similar, graphs, shortest paths

Make Nonzero Sum (hard version)

constructive algorithms, dp, greedy

Make Nonzero Sum (easy version)

constructive algorithms, dp, greedy

BinaryStringForces

constructive algorithms, data structures, dp

Complementary XOR

constructive algorithms, implementation

Indirect Sort

constructive algorithms, implementation, math

Cactus Wall

constructive algorithms, dfs and similar, graphs, shortest paths

Circular Xor Reversal

bitmasks, constructive algorithms

ConstructOR

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

Yet Another Problem

binary search, bitmasks, constructive algorithms, data structures

BAN BAN

constructive algorithms

Two Groups

constructive algorithms, greedy

Joking (Easy Version)

binary search, constructive algorithms, interactive, ternary search

Permutation Operations

constructive algorithms, greedy, implementation, math

Rebellion

constructive algorithms, greedy, two pointers

Maxmina

constructive algorithms, greedy

Antifibonacci Cut

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

Save the Magazines

constructive algorithms, dp, greedy

Permutation Value

constructive algorithms, greedy

Smaller

constructive algorithms, greedy, strings

Funny Permutation

constructive algorithms, math

Dangerous Laser Power

constructive algorithms, dsu, sortings

Hanging Hearts

constructive algorithms, data structures, dfs and similar, dp, greedy, trees

Knowledge Cards

constructive algorithms, data structures

Bricks and Bags

constructive algorithms, games, greedy, sortings

Factorise N+M

constructive algorithms, number theory

Card Game

combinatorics, constructive algorithms, dp, games

Array Recovery

constructive algorithms, greedy, math

Anti-Increasing Addicts

constructive algorithms, dp, greedy, math

Connectivity Addicts

constructive algorithms, dsu, graphs, greedy, interactive, shortest paths, trees

Permutation Addicts

constructive algorithms, data structures, dfs and similar, dsu, graphs, trees

Prefix Sum Addicts

constructive algorithms, greedy, math, sortings

Ela and Prime GCD

constructive algorithms, math, number theory

Ela and Crickets

constructive algorithms, games, implementation, math

Equal Binary Subsequences

constructive algorithms, geometry, greedy, implementation, strings

House Planning

constructive algorithms, data structures, graph matchings, greedy

Working Week

constructive algorithms, greedy, math

Rectangular Congruence

constructive algorithms, number theory

Bright, Nice, Brilliant

constructive algorithms

Conveyor

constructive algorithms, dp, math

Zero-One (Easy Version)

constructive algorithms, greedy, math

Parity Shuffle Sorting

constructive algorithms, sortings

Rule of League

constructive algorithms, math

Bestie

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

Prefixes and Suffixes

constructive algorithms, strings, two pointers

Jumping on Tiles

constructive algorithms, strings

Letter Picking

constructive algorithms, dp, games, two pointers

Best Permutation

constructive algorithms, greedy

Edge Split

brute force, constructive algorithms, dfs and similar, dsu, graphs, probabilities, trees

Mainak and Interesting Sequence

bitmasks, constructive algorithms, math

Hot Black Hot White

constructive algorithms, math

Even-Odd XOR

bitmasks, constructive algorithms, greedy

Matching Reduction

brute force, constructive algorithms, dfs and similar, flows, graph matchings, graphs, interactive

Misha and Paintings

constructive algorithms, data structures, greedy, implementation, math

Mathematical Circus

constructive algorithms, math

Impressionism

constructive algorithms, graphs, implementation, math

Madoka and The First Session

constructive algorithms, flows, graph matchings, graphs, implementation

Madoka and The Corruption Scheme

combinatorics, constructive algorithms, greedy, math

Madoka and Underground Competitions

constructive algorithms, implementation

Permutation Chain

constructive algorithms, math

Crop Squares

constructive algorithms, geometry, interactive, math

Beautiful Array

constructive algorithms, greedy, math

Crossmarket

constructive algorithms, greedy, math

Build a Tree and That Is It

constructive algorithms, implementation, trees

Lost Array

bitmasks, combinatorics, constructive algorithms, dp, math

Tournament Countdown

constructive algorithms, greedy, interactive, number theory, probabilities

Build Permutation

constructive algorithms, dp, math

Optimal Reduction

constructive algorithms, sortings

Empty Graph

binary search, constructive algorithms, data structures, greedy, shortest paths

Woeful Permutation

constructive algorithms, greedy, number theory

Perfect Permutation

constructive algorithms

Recover the Tree

constructive algorithms, trees

XOR Triangle

bitmasks, brute force, constructive algorithms, dp, greedy, math

Color the Picture

constructive algorithms, greedy, math

Recover an RBS

constructive algorithms, greedy, implementation, strings

Difference of GCDs

constructive algorithms, math

Bugaboo

bitmasks, constructive algorithms, dp, number theory

Doremy's IQ

binary search, constructive algorithms, greedy, implementation

Chopping Carrots (Hard Version)

brute force, constructive algorithms, data structures, dp, greedy, math, number theory, two pointers

Chopping Carrots (Easy Version)

binary search, brute force, constructive algorithms, greedy, number theory

Another String Minimization Problem

2-sat, constructive algorithms, greedy, string suffix structures, strings