Not Sitting

games, greedy, sortings

Not Shading

constructive algorithms, implementation

A Random Code Problem

combinatorics, dp, math, number theory, probabilities

Black and White Tree

dfs and similar, greedy, trees

Martial Arts Tournament

binary search, brute force, greedy, math

Monsters And Spells

binary search, data structures, dp, greedy, implementation, math, two pointers

Minor Reduction

greedy, strings

Equidistant Letters

constructive algorithms, sortings

Cats on the Upgrade (hard version)

binary search, data structures, dfs and similar, graphs, trees

Cats on the Upgrade (easy version)

brute force, data structures, dfs and similar, divide and conquer, dp, graphs, trees

Binary Spiders

bitmasks, data structures, implementation, math, sortings, trees

Road Optimization

dp

Elementary Particles

brute force, greedy, sortings

Ancient Civilization

bitmasks, greedy, math

MinOr Tree

bitmasks, dfs and similar, dsu, graphs, greedy

Interacdive Problem

binary search, constructive algorithms, interactive

Masha-forgetful

brute force, constructive algorithms, dp, hashing, implementation, strings

Palindromes Coloring

binary search, greedy, sortings, strings

Division by Two and Permutation

constructive algorithms, flows, graph matchings, greedy, math

Make AP

implementation, math

Plus One on the Subset

math

Middle Duplication

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

Robot Cleaner Revisit

implementation, math, probabilities

Balanced Stone Heaps

binary search, greedy

Game on Ranges

brute force, dfs and similar, implementation, sortings

Robot Cleaner

brute force, implementation, math

Quadratic Set

constructive algorithms, hashing, math, number theory

Math Test

bitmasks, brute force, greedy

Shuffle

combinatorics, math, two pointers

Set or Decrease

binary search, brute force, greedy, sortings

Berland Music

data structures, greedy, math, sortings

Construct a Rectangle

geometry, math

Two Sequences

data structures, hashing, string suffix structures

Trains and Airplanes

dfs and similar, graphs, shortest paths, trees

Weighted Increasing Subsequences

data structures, dp, math

Strange Instructions

data structures, greedy, implementation

New School

binary search, data structures, dp, greedy, implementation, sortings

The Winter Hike

constructive algorithms, greedy, math

Hidden Permutations

dfs and similar, interactive, math

Integers Shop

data structures, greedy, implementation

Stable Arrangement of Rooks

constructive algorithms

Subsequences Galore

bitmasks, combinatorics, dp

Bipartite Array

dp, greedy

Replace the Numbers

constructive algorithms, data structures, dsu, implementation

Exact Change

brute force, constructive algorithms, greedy

BA-String

brute force, dp, greedy, implementation, math

Triangles on a Rectangle

geometry, greedy, math

Equal or Not Equal

constructive algorithms, dsu, implementation

Permutation and Queries

brute force, data structures, divide and conquer, two pointers

Unusual Minesweeper

binary search, dfs and similar, dsu, greedy, sortings

Let's Play the Hat?

brute force, constructive algorithms, greedy, math

MEX and Increments

constructive algorithms, data structures, dp, greedy, implementation, math, sortings

New Year's Problem

binary search, greedy, sortings

Wrong Addition

implementation

Squares and Cubes

implementation, math

Square String?

implementation, strings

Trader Problem

data structures, dsu, greedy, sortings

Reverse

bitmasks, constructive algorithms, dfs and similar, implementation, math, strings

Singers' Tour

constructive algorithms, math

Array and Operations

dp, greedy, math

Paint the Array

math

Missing Bigram

implementation

Polycarp and Sums of Subsequences

math, sortings

Christmas Chocolates

dfs and similar, dp, games, graphs, implementation, math, number theory, shortest paths, trees

Too Many Impostors (hard version)

constructive algorithms, implementation, interactive, math

Too Many Impostors (easy version)

constructive algorithms, implementation, interactive

Paprika and Permutation

binary search, greedy, math, sortings

GCD Problem

brute force, constructive algorithms, math, number theory

Forbidden Subsequence

constructive algorithms, greedy, sortings, strings

Keep XOR Low

bitmasks, combinatorics, data structures, divide and conquer, dp, math

Just Add an Edge

dfs and similar, dp, graphs

Tricolor Triangles

brute force, graphs, math, matrices

Lexicographically Small Enough

brute force, data structures, greedy, strings

Keep the Average High

dp, greedy, math

Representative Edges

brute force, geometry, implementation, math

Mirror in the String

greedy, strings

Integer Diversity

implementation

Reindeer Games

binary search, constructive algorithms, data structures, divide and conquer, flows, graphs, shortest paths

Maximum Adjacent Pairs

constructive algorithms, graph matchings

LEGOndary Grandmaster

combinatorics, dp, math

Purple Crayon

data structures, dfs and similar, games, graphs, greedy, math, sortings, trees

X(or)-mas Tree

bitmasks, dfs and similar, dsu, graphs, trees

Menorah

brute force, graphs, greedy, math

And It's Non-Zero

bitmasks, greedy, math

Closing The Gap

greedy, math

Divan and a Cottage

binary search, data structures

Divan and Kostomuksha (hard version)

dp, number theory

Divan and Kostomuksha (easy version)

dp, number theory

Divan and bitwise operations

bitmasks, combinatorics, constructive algorithms, dp, math

Divan and a New Project

constructive algorithms, sortings

Divan and a Store

brute force, constructive algorithms, greedy

Tree Coloring

combinatorics, divide and conquer, fft

Crazy Robot

dfs and similar, graphs

MEX Sequences

dp, math

Poisoned Dagger

binary search

Absent Remainder

greedy, implementation, sortings

Long Comparison

implementation, math

Max Sum Array

combinatorics, constructive algorithms, greedy, sortings

Armor and Weapons

brute force, dp, greedy, shortest paths

Messages

brute force, dp, greedy, probabilities, sortings