Weird Sum

combinatorics, data structures, geometry, math, matrices, sortings

Madoka and the Sixth-graders

data structures, dfs and similar, greedy

Expand the Path

brute force, combinatorics, data structures, implementation, math

Cross Coloring

data structures, implementation, math

Anonymity Is Important

binary search, brute force, data structures, dsu, greedy, sortings

Two Posters

brute force, data structures, greedy, two pointers

Colorful Operations

brute force, data structures, implementation

Big Brush

constructive algorithms, data structures, greedy, implementation

Inversion Graph

data structures, dsu, graphs, math

Odd Swap Sort

data structures, math, sortings

Minimize Inversions Number

data structures, greedy, math, sortings

Closest Pair

data structures, greedy

Fibonacci Additions

brute force, data structures, hashing, implementation, math

Fair Share

constructive algorithms, data structures, dfs and similar, graph matchings, graphs

Perfect Matching

data structures, divide and conquer, interactive, trees

Spanning Tree Queries

binary search, data structures, dfs and similar, dsu, graphs, greedy, math, sortings, trees

Distance Tree (easy version)

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

New Year Concert

binary search, data structures, greedy, math, number theory, two pointers

Range and Partition

binary search, constructive algorithms, data structures, greedy, two pointers

Spaceship Crisis Management

binary search, data structures, geometry, sortings

Groceries in Meteor Town

binary search, data structures, dsu, trees

Not Escaping

data structures, dp, implementation, shortest paths, two pointers

Monsters And Spells

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

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

Middle Duplication

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

Berland Music

data structures, greedy, math, sortings

Two Sequences

data structures, hashing, string suffix structures

Weighted Increasing Subsequences

data structures, dp, math

Strange Instructions

data structures, greedy, implementation

New School

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

Integers Shop

data structures, greedy, implementation

Replace the Numbers

constructive algorithms, data structures, dsu, implementation

Permutation and Queries

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

MEX and Increments

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

Trader Problem

data structures, dsu, greedy, sortings

Keep XOR Low

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

Lexicographically Small Enough

brute force, data structures, greedy, strings

Reindeer Games

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

Purple Crayon

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

Divan and a Cottage

binary search, data structures

Robot and Candies

data structures, graph matchings, greedy

ATM and Students

binary search, data structures, two pointers

Squid Game

data structures, dfs and similar, greedy, trees

AmShZ Wins a Bet

data structures, greedy, hashing

A Stroll Around the Matrix

data structures, greedy, math

Interesting Sections

data structures, divide and conquer, meet-in-the-middle, two pointers

William The Oblivious

bitmasks, data structures, dp, matrices

Alphabetic Tree

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

Game Master

data structures, dfs and similar, dp, graphs, greedy, two pointers

Phys Ed Online

data structures, dp, greedy

Difficult Mountain

data structures, dp, greedy, sortings

Optimal Insertion

data structures, divide and conquer, dp, greedy, sortings

Frog Traveler

data structures, dfs and similar, dp, graphs, shortest paths, two pointers

Desert

data structures, graphs

Two Arrays

data structures, matrices

RBS

binary search, bitmasks, brute force, data structures, dp

Staircases

brute force, combinatorics, data structures, dfs and similar, dp, implementation, math

Training Session

combinatorics, data structures, geometry, implementation, math

Delete Two Elements

data structures, dp, implementation, math, two pointers

Changing Brackets

constructive algorithms, data structures, dp, greedy

Gardener and Tree

brute force, data structures, dfs and similar, greedy, implementation, trees

Jumping Through the Array

binary search, data structures, graphs, two pointers

Frequency Queries

data structures, dfs and similar, trees

Yet Another Sorting Problem

data structures, math

Game with Stones

binary search, data structures, games, greedy

Omkar and Tours

data structures, divide and conquer, sortings, trees

Omkar and Time Travel

data structures, math

Omkar and Determination

data structures, dp

Kuzya and Homework

data structures, number theory

Pchelyonok and Segments

binary search, data structures, dp, greedy, math

Grandma Capa Knits a Scarf

brute force, data structures, greedy, strings, two pointers

Railway Construction

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

Train Maintenance

brute force, data structures, implementation

Portal

brute force, data structures, dp, greedy, implementation

Array Optimization by Deque

data structures, greedy

Just Kingdom

brute force, data structures, dfs and similar

Building Forest Trails

data structures, dsu

Managing Telephone Poles

data structures, geometry

Longest Array Deconstruction

data structures, divide and conquer, dp, sortings

Illusions of the Desert

data structures, trees

Eye-Pleasing City Park Tour

data structures, trees

Cyclic Sum

data structures, fft, number theory

Another Sorting Problem

data structures, sortings, strings

The Strongest Build

binary search, brute force, data structures, dfs and similar, graphs, greedy, hashing, implementation

Stations

data structures

Book

binary search, brute force, data structures, dp, graphs, implementation, sortings

Physical Examination

*special problem, binary search, data structures

A Battle Against a Dragon

*special problem, data structures, dp

Inconvenient Pairs

binary search, data structures, implementation, sortings, two pointers

Non-Decreasing Dilemma

data structures, divide and conquer, math

Four Vertices

constructive algorithms, data structures, graphs, greedy, implementation, shortest paths

Points Movement

data structures, dp, greedy, implementation, sortings

Seating Arrangements (hard version)

data structures, greedy, implementation, sortings, two pointers

Seating Arrangements (easy version)

data structures, greedy, sortings

Two Hundred Twenty One (hard version)

data structures, math

Two Hundred Twenty One (easy version)

data structures, dp, math

Up the Strip (simplified version)

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

Strange Sort

data structures, sortings