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

Blackslex and Girls

constructive algorithms, geometry, math

Blackslex and Penguin Civilization

bitmasks, constructive algorithms, greedy, math

Blackslex and Number Theory

implementation, math, number theory, sortings

Blackslex and Showering

dp, greedy, implementation

Blackslex and Password

math, strings

Numbers or Fireworks

bitmasks, combinatorics, dp, graphs

Create or Duplicate

bitmasks, graphs, number theory, shortest paths

deCH OR Dations

bitmasks, data structures, dp, hashing, probabilities

Conquer or of Forest

combinatorics, math, trees

Flatten or Concatenate

binary search, divide and conquer, interactive

Xmas or Hysteria

constructive algorithms, greedy, implementation, math

First or Second

dp, greedy, implementation

Impost or Sus

dp, greedy, implementation, strings

Yes or Yes

greedy, strings

Omega Numbers

bitmasks, combinatorics, dp, math, number theory

Remove at the lowest cost

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

Fibonacci Paths

data structures, dp, graphs, sortings

Odd Process

greedy, sortings

Optimal Shifts

bitmasks, greedy, strings

Operations with Inversions

greedy, implementation, math

XOR Array

constructive algorithms, math

Little Fairy's Painting

implementation

Mosaic Tree

combinatorics, dp, fft, math, trees

Game of Scientists (Version 2)

binary search, chinese remainder theorem, dfs and similar, interactive, math

Game of Scientists (Version 1)

chinese remainder theorem, constructive algorithms, interactive, math

Secret Message

data structures, dp, greedy, trees

Beautiful Patterns (Hard Version)

combinatorics, math, probabilities

Beautiful Patterns (Easy Version)

combinatorics, math, probabilities

Wishing Cards

dp

Needle in a Haystack

greedy, strings, two pointers

Isla's Memory Thresholds

binary search, brute force, data structures, divide and conquer, math

Shiro's Mirror Duel

constructive algorithms, greedy, interactive, probabilities, sortings

Taiga's Carry Chains

bitmasks, brute force, dp, greedy, math

Kanade's Perfect Multiples

brute force, constructive algorithms, greedy, number theory

Niko's Tactical Cards

dp, greedy, math

Sleeping Through Classes

greedy, implementation

New Kingdom

constructive algorithms, graphs, implementation

Maximum Distance To Port

graphs, shortest paths

Maximum Color Segment

dp, implementation

Kindergarten Homework

implementation, strings

Sliding Tiles

data structures, divide and conquer, dsu

Birthday

geometry

Shuffling Cards with Problem Solver 68!

hashing, string suffix structures, strings

Gene Editor

Cluster Computing System

graphs, greedy, math

Number Maze

implementation

Divisor Card Game

combinatorics, dp

Circles Are Far from Each Other

binary search, greedy

Buses

greedy, sortings

ASCII Art Contest

implementation

Shiori Miyagi and Maximum Array Score

binary search, data structures, dp, sortings

Sakura Adachi and Optimal Sequences

bitmasks, combinatorics, greedy, math

Rae Taylor and Trees (hard version)

binary search, constructive algorithms, data structures, dp, dsu, greedy, implementation, trees

Anisphia Wynn Palettia and Good Permutations

constructive algorithms, greedy, number theory

Rae Taylor and Trees (easy version)

binary search, data structures, dp, dsu, greedy, implementation, trees

Renako Amaori and XOR Game (hard version)

bitmasks, games, greedy

Renako Amaori and XOR Game (easy version)

bitmasks, games, greedy

Yuu Koito and Minimum Absolute Sum

math

Shizuku Hoshikawa and Farm Legs

brute force, math

Build XOR on a Segment

bitmasks, dp

Binary Strings and Blocks

combinatorics, data structures, dp

Almost Roman

constructive algorithms, greedy, implementation

Quotient and Remainder

binary search, greedy, two pointers

Addition on a Segment

greedy, math

Maximum Neighborhood

bitmasks, brute force, greedy, implementation, math

Subsequence Problem

combinatorics, dp, fft, math

Points Selection

dp, greedy

Removal of a Sequence (Hard Version)

binary search, divide and conquer, greedy, implementation, math, number theory

Removal of a Sequence (Easy Version)

binary search, implementation, math, number theory