Strange device

binary search, interactive, math, trees

Turing's Award

data structures, dp

Fake bullions

combinatorics, dfs and similar, dp, graphs, number theory

Rap God

data structures, dfs and similar, hashing, strings, trees

Balls and Pockets

data structures

Multiple of Three Cycles

combinatorics, data structures, dp, dsu, math

Differentiating Games

games, interactive

Don't Exceed

math, probabilities

Upside Down

data structures, string suffix structures, strings, trees

Organizing a Music Festival

dfs and similar, math

Beauty of a Permutation

constructive algorithms, math

Pisces

data structures, flows, trees

Minimum Segments

constructive algorithms

Harder Satisfiability

2-sat, dfs and similar, graphs

Red-Blue Graph

dp, graphs, math, matrices, meet-in-the-middle

Yet Yet Another Permutation Problem

divide and conquer, fft, math

Mateusz and an Infinite Sequence

bitmasks, brute force, dp, strings

Shady Lady

geometry, math

Long number

expression parsing, math, number theory

Tokitsukaze and Powers

number theory, probabilities

Negative Time Summation

constructive algorithms

Cyclic Hamming (Easy Version)

brute force, divide and conquer, dp, fft, math, number theory

Bad Cryptography

math, number theory

Railway Construction

brute force, constructive algorithms, data structures, graphs, shortest paths

Lada Malina

data structures, geometry

Intergalactic Sliding Puzzle

combinatorics, constructive algorithms, math

Geolocation

geometry

Zero-XOR Array

*special problem, dp

Kuroni and Antihype

bitmasks, brute force, dp, dsu, graphs

Beautiful Fibonacci Problem

constructive algorithms, number theory

Replace

binary search, data structures

Intervals of Intervals

binary search, data structures, two pointers

Beautiful fountains rows

data structures

Density of subarrays

dp, math

Cactus Revenge

constructive algorithms

Chip Game

games

Making Shapes

dp

Cupboards Jumps

dp

Rin and The Unknown Flower

constructive algorithms, greedy, interactive, math

Nora's Toy Boxes

bitmasks, combinatorics, dp

Minimize Inversions Number

data structures, greedy, math, sortings

Chiori and Doll Picking (hard version)

bitmasks, brute force, combinatorics, math

Modest Substrings

dp, strings

My Beautiful Madness

data structures, trees

XOR-ranges

dp, greedy

Jumping Through the Array

binary search, data structures, graphs, two pointers

Just Add an Edge

dfs and similar, dp, graphs

Range Diameter Sum

data structures, trees

Zigzag Game

games, interactive

Holy Diver

data structures

Hopping Around the Array

data structures, dp

Communism

bitmasks, dp, trees

Bully Sort

data structures, math

JYPnation

graphs

Xor on Figures

constructive algorithms, fft, math

The Fair Nut's getting crazy

data structures, implementation

Forest Fires

math

Breadboard Capacity (hard version)

Ж-function

string suffix structures, strings

Stock Exchange

binary search, flows, graphs

Become Big For Me

combinatorics, constructive algorithms, greedy, math, number theory

Speckled Band

data structures, divide and conquer, hashing, string suffix structures, strings

OH NO1 (-2-3-4)

constructive algorithms, graphs, math

Cheat and Win

bitmasks, data structures, games, trees

Phoenix and Bits

bitmasks, brute force, data structures, sortings

Old Mobile

combinatorics, dp, probabilities

Journey

data structures, divide and conquer, graphs, trees

Euler tour

constructive algorithms, trees

Flow Control

data structures, dsu, implementation

School Clubs

dp, fft, math, number theory, probabilities

New Year and Snowy Grid

dfs and similar, dsu, graphs, interactive

Minecraft Series

brute force, two pointers

Entangled Substrings

string suffix structures, strings

Growing flowers

data structures

Cacti Symphony

combinatorics, dfs and similar, dp, graphs

Epic Convolution

chinese remainder theorem, fft, math, number theory

Tree LGM

constructive algorithms, divide and conquer, games, trees

A Convex Game

dsu, games

Trains and Airplanes

dfs and similar, graphs, shortest paths, trees

Cursor Distance

Omkar and Mosaic

combinatorics, constructive algorithms, math

Jellyfish and OEIS

dp

Mateusz and Escape Room

dp

Maximum Product?

brute force, combinatorics, dp, greedy, implementation, math, two pointers

Alphabetic Tree

binary search, data structures, dfs and similar, hashing, string suffix structures, strings, trees

Blocks and Sensors

brute force

BubbleSquare Tokens

Good Graph

bitmasks, dfs and similar, graph matchings, graphs, implementation

Bugaboo

bitmasks, constructive algorithms, dp, number theory

Lost Nodes

constructive algorithms, dp, graphs, interactive, sortings, trees

The Ultimate LIS Problem

data structures, greedy

Red Blue Tree

data structures, implementation, trees

Balance the Cards

constructive algorithms, data structures, divide and conquer, geometry, graphs, implementation

Optimizations From Chelsu

divide and conquer, dp, number theory, trees

Olympic Team Building

brute force, meet-in-the-middle

Finding the Vertex

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

Dušan's Railway

divide and conquer, graphs, trees

Anti-Proxy Attendance

constructive algorithms, dp, interactive, ternary search

Maximum Permutation

constructive algorithms

Boboniu and Banknote Collection

strings