Maximums and Minimums

combinatorics, data structures, divide and conquer, number theory

Prefixes and Suffixes

constructive algorithms, strings, two pointers

Meeting on the Line

binary search, geometry, greedy, implementation, math, ternary search

Cut Substrings

combinatorics, dp, hashing, strings, two pointers

Kirei and the Linear Function

hashing, math

Guess the Cycle Size

interactive, probabilities

Illumination

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

Fishermen

flows, graph matchings, greedy

Red-Black Pepper

brute force, data structures, greedy, math, number theory

Letter Picking

constructive algorithms, dp, games, two pointers

Digital Logarithm

data structures, greedy, sortings

Mainak and the Bleeding Polygon

binary search, geometry, implementation, math

A Certain Magical Party

combinatorics, data structures, greedy, sortings

Late For Work (submissions are not allowed)

data structures, greedy, schedules, shortest paths

Almost Perfect

combinatorics, fft, math

Edge Split

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

Moving Both Hands

dp, graphs, shortest paths

Lemper Cooking Competition

data structures

Kingdom of Criticism

data structures, dsu

Journey

dp, trees

Imitating the Key Tree

combinatorics, dsu, trees

Hot Black Hot White

constructive algorithms, math

Garage

binary search, geometry, math

Field Photography

bitmasks, data structures, sortings

Electrical Efficiency

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

Deducing Sortability

binary search, bitmasks, math

Circular Mirror

binary search, combinatorics, geometry, math, two pointers

Even-Odd XOR

bitmasks, constructive algorithms, greedy

L-shapes

dfs and similar, implementation

Counting Rectangles

brute force, data structures, dp, implementation

Matching Reduction

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

Prefix Function Queries

dfs and similar, dp, hashing, string suffix structures, strings, trees

Maximum AND

bitmasks, dfs and similar, divide and conquer, greedy, sortings

Min-Max Array Transformation

binary search, greedy, two pointers

Misha and Paintings

constructive algorithms, data structures, greedy, implementation, math

Xor-Subsequence (hard version)

bitmasks, data structures, dp, strings, trees

Xor-Subsequence (easy version)

bitmasks, brute force, dp, strings, trees, two pointers

Fighting Tournament

binary search, data structures, implementation, two pointers

Burenka, an Array and Queries

data structures, math, number theory

Impressionism

constructive algorithms, graphs, implementation, math

Permutation for Burenka

data structures, graph matchings, greedy, math, trees

Tonya and Burenka-179

data structures, greedy, math, number theory

Fibonacci Strings

greedy, implementation, math, number theory

Burenka and Traditions (hard version)

data structures, dp, greedy

Burenka and Traditions (easy version)

dp, greedy

Madoka and The First Session

constructive algorithms, flows, graph matchings, graphs, implementation

Madoka and The Best University

math, number theory

Madoka and The Corruption Scheme

combinatorics, constructive algorithms, greedy, math

Bags with Balls

combinatorics, dp, math, number theory

Swap and Maximum Block

bitmasks, data structures, dfs and similar, divide and conquer, dp

Chip Move

brute force, dp, math

Robot in a Hallway

data structures, dp, greedy, implementation, ternary search

Crop Squares

constructive algorithms, geometry, interactive, math

Long Way Home

data structures, divide and conquer, dp, geometry, graphs, greedy, shortest paths

2+ doors

2-sat, bitmasks, graphs, greedy

Monoblock

combinatorics, data structures, implementation, math

Path Prefixes

binary search, data structures, dfs and similar, trees

Build a Tree and That Is It

constructive algorithms, implementation, trees

Add Modulo 10

brute force, math, number theory

Color with Occurrences

brute force, data structures, dp, greedy, strings

Lost Array

bitmasks, combinatorics, constructive algorithms, dp, math

Cross Swapping

2-sat, data structures, dsu, greedy, matrices

Tournament Countdown

constructive algorithms, greedy, interactive, number theory, probabilities

Triameter

binary search, data structures, dfs and similar, trees

LCM Sum (hard version)

brute force, data structures, math, number theory, two pointers

LCM Sum (easy version)

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

Empty Graph

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

Two Arrays

binary search, games, graph matchings

Recover the Tree

constructive algorithms, trees

XOR Triangle

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

Rain

binary search, brute force, data structures, geometry, greedy, implementation, math

Color the Picture

constructive algorithms, greedy, math

Multiset of Strings

bitmasks, brute force, dp, fft, flows, graphs, math, meet-in-the-middle, trees

XOR Tree

bitmasks, data structures, dfs and similar, dsu, greedy, trees

Rorororobot

binary search, data structures, greedy, math

Recover an RBS

constructive algorithms, greedy, implementation, strings

Bugaboo

bitmasks, constructive algorithms, dp, number theory

Replace

binary search, data structures

Partial Virtual Trees

combinatorics, dfs and similar, dp, math, trees

DFS Trees

dfs and similar, dsu, graphs, greedy, sortings, trees

Difference Array

brute force, data structures, implementation, sortings

Doremy's IQ

binary search, constructive algorithms, greedy, implementation

Qpwoeirut and Vertices

binary search, data structures, dfs and similar, divide and conquer, dsu, greedy, trees

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

Qpwoeirut And The City

dp, flows, greedy, implementation

Mark and the Online Exam

bitmasks, constructive algorithms, interactive, probabilities

Mark and Professor Koro

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

Mark and Lightbulbs

combinatorics, constructive algorithms, greedy, math, sortings

Mark and His Unfinished Essay

brute force, implementation

Game of AI (hard version)

combinatorics, fft, math

Game of AI (easy version)

combinatorics, constructive algorithms, dp, fft, math

Mio and Lucky Array

constructive algorithms, fft, math, strings

Colouring Game

constructive algorithms, dp, games

Count Seconds

brute force, constructive algorithms, dp, graphs, implementation, math

Magical Array

constructive algorithms, hashing, implementation, math

Good Key, Bad Key

bitmasks, brute force, dp, greedy, math

Passable Paths (hard version)

data structures, dfs and similar, trees

Passable Paths (easy version)

dfs and similar, trees

Equate Multisets

constructive algorithms, data structures, greedy, math, number theory