Pizza Delivery

dp, greedy

Product Queries

dp, math, number theory, shortest paths

Monster Game

binary search, sortings, two pointers

Replace and Sum

data structures, greedy

Reverse a Permutation

greedy

DBMB and the Array

brute force, math

Fish Fight

dp, dp, math, probabilities, probabilities

Swap to Rearrange

constructive algorithms, dfs and similar, graph matchings, graphs, graphs, graphs, greedy, strings

Cost of Tree

dp, greedy, trees, trees

All-in-one Gun

binary search, greedy, math

Flipping Binary String

constructive algorithms, strings

String Rotation Game

brute force, strings

MEX Reordering

constructive algorithms, sortings

Array Coloring

constructive algorithms

Maximize Determinant

graphs

Xor Product

bitmasks, dp

Median Permutation

combinatorics

Prufer Vertex

combinatorics, dsu, number theory, probabilities, trees

Comparable Permutations

greedy, implementation, interactive, sortings, two pointers

Sub-RBS (Hard Version)

dp, games, implementation, strings

Sub-RBS (Easy Version)

combinatorics, constructive algorithms, dp, greedy, strings, two pointers

Sorting Game

constructive algorithms, games, greedy

Zhora the Vacuum Cleaner

data structures, dfs and similar, dp, greedy, implementation, sortings, trees

Majority Wins?

constructive algorithms, greedy, math, strings

Little String (Hard Version)

combinatorics, dp, greedy, math, number theory

Little String (Easy Version)

combinatorics, dp, greedy, math, number theory

XOR-convenience (Hard Version)

bitmasks, constructive algorithms, math

XOR Convenience (Easy Version)

bitmasks, constructive algorithms, math

The Curse of the Frog

constructive algorithms, greedy, math

Table with Numbers

greedy, implementation

Seats

greedy

Divisible Permutation

constructive algorithms

Many Cartesian Trees

greedy, sortings, trees

Al Fine (Counting Version)

dp, trees

Al Fine (Maximizing Version)

binary search, data structures, divide and conquer, trees

Doors and Keys

brute force, data structures, dp

Cool Problem

bitmasks, dp, math

Jerry and Tom

data structures, dfs and similar, dsu, games, graphs, greedy, trees

Shortest Statement Ever

bitmasks, constructive algorithms, dp, greedy

Restricted Sorting

greedy, sortings

BattleCows 2

binary search, brute force, data structures, dp, greedy

Mixing MEXes

data structures, implementation, math

BattleCows

data structures, divide and conquer, implementation

The Robotic Rush

binary search, greedy, implementation, two pointers

OutOfMemoryError

data structures, implementation, math, two pointers

Shifted MEX

implementation, sortings

Prefix Max

greedy

Perfect Root

constructive algorithms, math

Nastiness of Segments

binary search, data structures

Cherry Tree

dfs and similar, dp, graphs, trees

Exquisite Array

combinatorics, data structures, dsu, sortings

Unfair Game

combinatorics, dp, math

Huge Pile

binary search, dfs and similar, dp, graphs, math

Hourglass

math

Social Experiment

math

Pairs Flipping (Hard Version)

constructive algorithms

Pairs Flipping (Easy Version)

constructive algorithms

Minimise Cost

binary search, dp, greedy, sortings

Snake Instructions

constructive algorithms, greedy, interactive

Jumping Man

brute force, combinatorics, dfs and similar, dp, trees

LCM is Legendary Counting Master

dp, math, number theory

Tree Coloring (Hard Version)

combinatorics, constructive algorithms, data structures, dfs and similar, greedy, implementation, trees

Tree Coloring (Easy Version)

constructive algorithms, dfs and similar, greedy, trees

War Strategy

binary search, greedy, math, two pointers

Yet Another MEX Problem

constructive algorithms, greedy

Binary Array Game

games

Short Garland

combinatorics, data structures, dfs and similar, dp, trees

Christmas Reindeer (hard version)

bitmasks, brute force, combinatorics, data structures, greedy, math

Christmas Reindeer (easy version)

bitmasks, brute force, combinatorics, dp, math

New Year's Gifts

binary search, data structures, greedy, sortings, two pointers

Christmas Tree Decoration

combinatorics, dp, greedy, math

Production of Snowmen

brute force, combinatorics, dp

New Year Cake

brute force

New Year String

constructive algorithms, greedy, implementation, strings

Medical Parity

dp, strings

LLM Training

math, string suffix structures

Knit the Grid

2-sat, constructive algorithms, graphs, matrices

Jinx or Jackpot

brute force, dp, math, probabilities

Irrigation Interlock

geometry

Honey Cake

brute force, math, number theory

Greta's Game

binary search, dp, graphs, greedy, math

Fragmented Nim

games

Elevator Against Humanity

brute force, constructive algorithms, greedy, sortings

Doorway

binary search, data structures, sortings

Cacti Classification

binary search, constructive algorithms, interactive, math

Battle of Arrays

data structures, games, greedy

Alphabet City

binary search, math, strings

Bug Is Feature (Conditional Version)

games

Bug Is Feature (Unconditional Version)

games

Balance

bitmasks, combinatorics, implementation, math

Control Car (Hard Version)

combinatorics, dp, matrices, probabilities

Control Car (Easy Version)

combinatorics, dp, probabilities

No Effect XOR

bitmasks, divide and conquer, dp, greedy, math

Insolvable Disks

data structures, dp, greedy, math

XOR-factorization

bitmasks, constructive algorithms, dp, greedy, number theory

Ashmal

greedy, strings

Carnival Wheel

brute force, number theory

Blackslex and Plants

bitmasks, data structures, dp, implementation, math

Blackslex and Penguin Migration

brute force, interactive, math

Blackslex and Another RGB Walking

communication, constructive algorithms, graphs, interactive, number theory, trees