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

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

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

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

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

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

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

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

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

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

New Kingdom

constructive algorithms, graphs, implementation

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

Divisor Card Game

combinatorics, dp

Circles Are Far from Each Other

binary search, greedy

Buses

greedy, sortings

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

Build XOR on a Segment

bitmasks, dp

Binary Strings and Blocks

combinatorics, data structures, dp

Almost Roman

constructive algorithms, greedy, implementation

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

Mukhammadali and the Smooth Array

data structures, dp

Tree, TREE!!!

dfs and similar, dp, math, trees

khba Loves to Sleep!

binary search, data structures, geometry, greedy, implementation

Arctic Acquisition

data structures, greedy

Rainbow Branch

constructive algorithms, dp, greedy, trees

Path Split

graph matchings, greedy

Binary Wine

bitmasks, greedy, math

Marble Council

dp, math, sortings

PalindromePalindrome

data structures, strings

Pointless Machine

constructive algorithms, graphs, interactive, trees

Chain Prefix Rank (Hard Version)

binary search, combinatorics, data structures, dfs and similar, dp, graphs, math, trees

Chain Prefix Rank (Easy Version)

combinatorics, dfs and similar, dp, math, trees

Journey

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

Copy String

greedy, implementation, strings, two pointers

Plegma

bitmasks, combinatorics, communication, interactive

Diadrash (Hard Version)

binary search, interactive, math, sortings

Diadrash (Easy Version)

binary search, brute force, divide and conquer, implementation, interactive

Siga ta Kymata

constructive algorithms, greedy, implementation, math

Beautiful Problem

dp

Beautiful Tree

constructive algorithms, math, probabilities, trees

Beautiful Intervals

constructive algorithms, greedy

Beautiful Palindromes

constructive algorithms, greedy, schedules

Cycle Sort

data structures

Bitwise And Equals

bitmasks, greedy

SubMST

combinatorics, graphs, trees

Left is Always Right

combinatorics, implementation, math

Locked Out

binary search, data structures, dp, greedy