Playoff Fixing

combinatorics, trees

Good Graph

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

Old Mobile

combinatorics, dp, probabilities

Doctor's Brown Hypothesis

dfs and similar, graphs, math, number theory

Twin Clusters

bitmasks, brute force, constructive algorithms, math, probabilities

Lottery

binary search, brute force, greedy, math, two pointers

k-th equality

brute force, implementation, math

Typewriter

brute force, math

MEX of LCM

binary search, data structures, implementation, math, number theory

Survey in Class

brute force, data structures, greedy, implementation, sortings

Ksyusha and Chinchilla

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

Ira and Flamenco

combinatorics, constructive algorithms, data structures, implementation, math, sortings, two pointers

Round Dance

dfs and similar, dsu, graphs, shortest paths

Zombies

binary search, dp

Combinatorics Problem

brute force, combinatorics, dp

Red-Blue Operations (Hard Version)

binary search, constructive algorithms, greedy, implementation, math

Red-Blue Operations (Easy Version)

binary search, greedy, implementation, math

The Third Grace

data structures, dp

Bully Sort

data structures, math

Mex Tree

brute force, dp, trees

Hyperregular Bracket Strings

combinatorics, greedy, hashing, math, number theory, sortings

The BOSS Can Count Pairs

brute force, math

Don't Blame Me

bitmasks, combinatorics, dp, math

Hits Different

data structures, dp, implementation, math

Copium Permutation

constructive algorithms, data structures, greedy

Bus Routes

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

Two Centroids

data structures, dfs and similar, greedy, trees

Palindrome Partition

binary search, brute force, data structures, dp, hashing, strings

Range Sorting (Hard Version)

binary search, data structures, dp, greedy

Range Sorting (Easy Version)

binary search, dp, dsu, greedy, trees, two pointers

Fading into Fog

geometry, interactive, math, probabilities

Walk the Runway

bitmasks, brute force, data structures, dp, graphs, implementation, sortings

Running Miles

brute force, dp, greedy

LuoTianyi and Cartridge

data structures, trees

LuoTianyi and the Function

data structures

LuoTianyi and XOR-Tree

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

LuoTianyi and the Floating Islands (Hard Version)

combinatorics, dfs and similar, math, probabilities, trees

LuoTianyi and the Floating Islands (Easy Version)

combinatorics, math, probabilities, trees

Random Walk

dp, graphs, math, probabilities, trees

Removing Graph

brute force, dp, games, graphs, math

Unique Palindromes

constructive algorithms, math, strings

Magic Triples (Hard Version)

brute force, data structures, math, number theory

Magic Triples (Easy Version)

brute force, data structures, math, number theory

Gardening Friends

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

Making Anti-Palindromes

greedy, math, strings

Timber

combinatorics, dp, fft, math

Rearrange Brackets

brute force, dp, greedy, sortings, strings

Black Cells

binary search, brute force, greedy, math

Willy-nilly, Crack, Into Release!

data structures, dp

Roads in E City

interactive, math, probabilities, trees

Misha and Apples

brute force, data structures, dp, two pointers

The Fox and the Complete Tree Traversal

constructive algorithms, dp, implementation, math, trees

The Butcher

geometry, greedy, implementation, sortings, two pointers

Entangled Substrings

string suffix structures, strings

Half-sum

brute force, divide and conquer, greedy

Toy Machine

constructive algorithms, games, implementation

Similar Polynomials

combinatorics, math

Fish Graph

brute force, constructive algorithms, dfs and similar, graphs

OH NO1 (-2-3-4)

constructive algorithms, graphs, math

Bosco and Particle

dp, math, number theory, strings

XOR Counting

bitmasks, combinatorics, dp, math

Between

constructive algorithms, dfs and similar, graphs, greedy

Sum Graph

brute force, constructive algorithms, graphs, implementation, interactive, shortest paths, trees

Communication Towers

brute force, divide and conquer, dsu

Chain Chips

data structures, dp, matrices

Balancing Weapons

binary search, brute force, data structures, math, two pointers

Long Legs

brute force, math

Vlad and the Nice Paths (hard version)

binary search, combinatorics, data structures, dp, math, two pointers

Vlad and the Nice Paths (easy version)

combinatorics, dp, math

Is It Flower?

dfs and similar, graphs, implementation

Umka and a Long Flight

constructive algorithms, implementation, math

Last Number

combinatorics, math

The Maximum Prefix

dp

M-tree

data structures, math, sortings, trees

Monsters

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

Climbing the Tree

binary search, math

Prediction

combinatorics, dp, math

Traveling in Berland

binary search, data structures, graphs, greedy, implementation

Two Tanks

binary search, dp, implementation, math

Binary String Sorting

constructive algorithms, greedy

Minibuses on Venus (hard version)

brute force, combinatorics, dp, math

Minibuses on Venus (medium version)

combinatorics, divide and conquer, dp, matrices

Minibuses on Venus (easy version)

combinatorics, divide and conquer, dp

Petya, Petya, Petr, and Palindromes

binary search, brute force, data structures, two pointers

Unlucky Numbers

brute force, dp, greedy, implementation

Bouncy Ball

brute force, dfs and similar, implementation

GCD Master (hard version)

greedy, math, sortings

GCD Master (easy version)

greedy, math, number theory, sortings

Tree Master

brute force, data structures, dfs and similar, trees

DSU Master

combinatorics, dp, dsu, math

Sequence Master

brute force, constructive algorithms, math

Survival of the Weakest (hard version)

greedy, math, sortings, two pointers

Survival of the Weakest (easy version)

binary search, brute force, implementation, math, sortings

There Should Be a Lot of Maximums

brute force, data structures, dfs and similar, dp, trees, two pointers

A Wide, Wide Graph

dfs and similar, dp, graphs, greedy, trees

Code Lock

bitmasks, dp

Flow Control

data structures, dsu, implementation

Approximate Diameter

binary search, divide and conquer, graphs, shortest paths

Routing

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

Accommodation

brute force, dp, greedy, implementation