±1

2-sat, dfs and similar, graphs

Circle Perimeter

binary search, brute force, dfs and similar, geometry, implementation, math

Min-Fund Prison (Hard)

bitmasks, dfs and similar, dp, graphs, trees

Min-Fund Prison (Medium)

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

Min-Fund Prison (Easy)

dfs and similar, trees

Game on Tree (Hard)

dfs and similar, dp, games, trees

Game on Tree (Medium)

dfs and similar, dp, games, trees

Permutation Game

brute force, dfs and similar, games, graphs, greedy, math

Long Way to be Non-decreasing

binary search, dfs and similar, graphs, implementation, shortest paths, two pointers

Frequency Mismatch (Hard Version)

binary search, data structures, dfs and similar, hashing, probabilities, trees

GCD on a grid

brute force, dfs and similar, dp, implementation, math, number theory

Mathematician Takeover

binary search, dfs and similar, math

Shuffling Songs

bitmasks, dfs and similar, dp, graphs, hashing, implementation, strings

Disks

dfs and similar, geometry, graph matchings, graphs

Annual Ants' Gathering

dfs and similar, dp, greedy, trees

Grove

brute force, dfs and similar, dp, geometry, probabilities

Arrow Path

brute force, constructive algorithms, dfs and similar, dp, graphs, shortest paths

Nobody is needed

2-sat, data structures, dfs and similar, dp

Tree Compass

constructive algorithms, dfs and similar, greedy, trees

Learning to Paint

binary search, data structures, dfs and similar, dp, greedy, implementation, sortings

Rudolf and Subway

constructive algorithms, dfs and similar, graphs, shortest paths

Rudolf and the Ball Game

dfs and similar, dp, implementation

Burenka and Pether

*special problem, data structures, dfs and similar, divide and conquer, dsu, graphs, sortings, trees

Parallel Universes

*special problem, constructive algorithms, dfs and similar, dsu, graphs

More Gifts

*special problem, dfs and similar, two pointers

Evidence Board

*special problem, constructive algorithms, dfs and similar, graphs, trees

Andrey's Tree

binary search, constructive algorithms, data structures, dfs and similar, dsu, greedy, implementation, trees

Turtle Magic: Royal Turtle Shell Pattern

bitmasks, brute force, combinatorics, constructive algorithms, dfs and similar, math

Turtle Mission: Robot and the Earthquake

dfs and similar, dp, graphs, shortest paths

Chat Screenshots

combinatorics, dfs and similar, graphs

Interactive Mex Tree

constructive algorithms, dfs and similar, interactive, trees

Maximize the Difference

bitmasks, brute force, dfs and similar

Sasha and the Wedding Binary Search Tree

brute force, combinatorics, data structures, dfs and similar, math, trees

Sasha and the Happy Tree Cutting

bitmasks, brute force, dfs and similar, dp, graphs, greedy, math, trees

Microcycle

data structures, dfs and similar, dsu, graphs, greedy, implementation, sortings, trees

Vlad and Trouble at MIT

dfs and similar, dp, flows, graphs, greedy, implementation, trees

Vlad and Avoiding X

bitmasks, brute force, dfs and similar, dp, implementation

Count Paths

data structures, dfs and similar, dp, dsu, graphs, trees

Smooth Sailing (Easy Version)

binary search, brute force, data structures, dfs and similar, dsu, graphs, shortest paths

Caterpillar on a Tree

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

Group Division

constructive algorithms, dfs and similar, graphs, greedy

Happy Life in University

data structures, dfs and similar, greedy, trees

Light Bulbs (Hard Version)

combinatorics, data structures, dfs and similar, dp, graphs, hashing

Light Bulbs (Easy Version)

brute force, combinatorics, dfs and similar, dp, dsu, graphs, math, trees

Programming Competition

dfs and similar, dp, graph matchings, greedy, trees

Lights

brute force, constructive algorithms, dfs and similar, graphs, greedy, implementation

One-X

combinatorics, dfs and similar, dp, math, trees

Beautiful Tree

data structures, dfs and similar, graphs, implementation, trees

Tree Queries

data structures, dfs and similar, graphs, implementation, trees

Trees and XOR Queries Again

data structures, dfs and similar, divide and conquer, graphs, implementation, math, trees

Compressed Tree

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

Transitive Graph

dfs and similar, dp, dsu, graphs, implementation

Anji's Binary Tree

dfs and similar, dp, trees

Unusual Entertainment

data structures, dfs and similar, dsu, shortest paths, sortings, trees, two pointers

Vova Escapes the Matrix

brute force, dfs and similar, divide and conquer, shortest paths

Infinite Card Game

binary search, brute force, data structures, dfs and similar, dp, dsu, games, graphs, greedy, sortings, two pointers

Cacti Symphony

combinatorics, dfs and similar, dp, graphs

Anonymous Informant

brute force, dfs and similar, graphs, implementation

A Growing Tree

data structures, dfs and similar, trees

Doremy's Swapping Trees

dfs and similar, graphs, trees

Game of Stacks

brute force, dfs and similar, graphs, implementation, trees

Tree XOR

bitmasks, dfs and similar, dp, greedy, trees

Minimum Maximum Distance

dfs and similar, dp, graphs, shortest paths, trees

Interactive Game with Coloring

brute force, constructive algorithms, dfs and similar, graphs, implementation, interactive, trees

wxhtzdy ORO Tree

binary search, bitmasks, brute force, data structures, dfs and similar, implementation, trees

Lexichromatography

combinatorics, dfs and similar, dsu, graphs, two pointers

Autosynthesis

constructive algorithms, dfs and similar, graphs, greedy, sortings

Jellyfish and Math

bitmasks, brute force, dfs and similar, dp, graphs, shortest paths

Mad City

dfs and similar, dsu, games, graphs, shortest paths, trees

Selling a Menagerie

dfs and similar, dsu, graphs, implementation, math

Most Different Tree

brute force, constructive algorithms, dfs and similar, greedy, hashing

Cyclic Operations

brute force, constructive algorithms, dfs and similar, graphs, greedy, implementation

Completely Searching for Inversions

dfs and similar, dp, graphs

Speedrun

brute force, dfs and similar, dp, graphs, greedy, math, sortings, two pointers

Queries for the Array

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

Fast Travel Text Editor

data structures, dfs and similar, graphs, shortest paths

Teleportation in Byteland

data structures, dfs and similar, divide and conquer, graphs, shortest paths, trees

Rollbacks (Easy Version)

brute force, data structures, dfs and similar, trees

PermuTree (hard version)

bitmasks, dfs and similar, dp, fft, greedy, implementation, math, trees

PermuTree (easy version)

dfs and similar, dp, trees

Nastya and Potions

dfs and similar, dp, graphs, sortings

The Third Letter

dfs and similar, dsu, graphs, greedy, implementation

The Boss's Identity

binary search, bitmasks, data structures, dfs and similar, greedy, math, sortings

Tree Weights

bitmasks, constructive algorithms, data structures, dfs and similar, implementation, math, matrices, number theory, trees

Great Grids

2-sat, constructive algorithms, dfs and similar, dsu, graphs

Omsk Metro (hard version)

data structures, dfs and similar, divide and conquer, dp, math, trees

Omsk Metro (simple version)

data structures, dfs and similar, dp, graphs, greedy, math, trees

Apple Tree

combinatorics, dfs and similar, dp, math, trees

Tenzing and Tree

dfs and similar, greedy, shortest paths, sortings, trees

Railguns

brute force, dfs and similar, dp, graphs

Decreasing Game

constructive algorithms, dfs and similar, dp, greedy, interactive

Good Graph

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

Doctor's Brown Hypothesis

dfs and similar, graphs, math, number theory

Ksyusha and Chinchilla

constructive algorithms, dfs and similar, dp, dsu, greedy, implementation, trees

Round Dance

dfs and similar, dsu, graphs, shortest paths

Copil Copac Draws Trees

dfs and similar, dp, graphs, trees

Forever Winter

dfs and similar, graphs, math

The Lakes

dfs and similar, dsu, graphs, implementation

Gold Rush

brute force, dfs and similar, dp, implementation

Bus Routes

binary search, constructive algorithms, dfs and similar, greedy, trees