Construct Tree

bitmasks, constructive algorithms, dp, trees

Construct Matrix

constructive algorithms, math

Yet Another Inversions Problem

combinatorics, data structures, dp, implementation, math, number theory

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

Matrix Problem

flows, graphs

Array Collapse

data structures, divide and conquer, dp, trees

Joy of Pokémon Observation

Hypercatapult Commute

graphs

Great City Saint Petersburg

data structures

Evaluate It and Back Again

constructive algorithms, implementation, math

Blueprint for Seating

combinatorics, divide and conquer, math

Sum of Digits of Sums

*special problem, binary search, data structures

Build Railway Stations

*special problem, greedy, trees

Maximum Sum Subarrays

*special problem, dp

Small Permutation Problem (Hard Version)

combinatorics, dp, math

Small Permutation Problem (Easy Version)

brute force, combinatorics, dp, math

Multiple Lamps

bitmasks, brute force, constructive algorithms, math, number theory

Lights

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

Palindromic Parentheses

constructive algorithms

Deck-Building Game

divide and conquer, math

Count BFS Graph

combinatorics, dp

Twin Friends

combinatorics, dp

Maximize The Value

data structures, sortings

One-X

combinatorics, dfs and similar, dp, math, trees

Cyclic MEX

data structures, implementation, math, two pointers

Tree Queries

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

Babysitting

2-sat, binary search, data structures, graphs, trees

Geo Game

greedy, interactive, math

Maximum And Queries (hard version)

bitmasks, divide and conquer, dp, greedy

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

Small GCD

bitmasks, brute force, dp, math, number theory

Sofia and Strings

data structures, greedy, sortings, strings, two pointers

Permutation Sorting

data structures, sortings

Infinite Card Game

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

Freedom of Choice

brute force, greedy, implementation

A Growing Tree

data structures, dfs and similar, trees

Brukhovich and Exams

brute force, greedy, implementation, math, sortings

Doremy's Drying Plan (Easy Version)

brute force, data structures, dp, greedy, sortings

Minimum Array

binary search, brute force, constructive algorithms, data structures, greedy, hashing, two pointers

I Wanna be the Team Leader

bitmasks, constructive algorithms, dp, greedy, math, sortings, two pointers

Monocarp and the Set

combinatorics, data structures, math

Counting Rhyme

dp, math, number theory

Two Permutations (Easy Version)

brute force, constructive algorithms, greedy, number theory

Anya and the Mysterious String

binary search, data structures

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 EVA

dp, graphs, greedy, math, probabilities

Jellyfish and Math

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

Replace With Product

brute force, greedy, math

Another MEX Problem

bitmasks, brute force, dp, shortest paths

Travel Plan

combinatorics, dp, implementation, math, trees

Candy Party (Hard Version)

bitmasks, constructive algorithms, dp, greedy, implementation, math

Salyg1n and Array (hard version)

constructive algorithms, interactive

Salyg1n and Array (simple version)

constructive algorithms, interactive, math

Mighty Rock Tower

brute force, combinatorics, dp, math, probabilities

Lihmuf Balling

binary search, brute force, math

Keen Tree Calculation

binary search, data structures, dp, geometry, graphs, implementation, trees

Imagination Castle

dp, games, two pointers

Happy Sets

combinatorics

Grouped Carriages

binary search, data structures, dp, flows, greedy

Digital Wallet

dp, greedy

Exotic Queries

data structures, implementation, sortings

Guess Game

bitmasks, data structures, games, math, probabilities, sortings, strings, trees

Speedrun

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

The Great Equalizer

binary search, data structures, math, sortings

Non-Intersecting Subpermutations

combinatorics, dp, implementation, math

Fast Travel Text Editor

data structures, dfs and similar, graphs, shortest paths

Balanced String

dp

Maximum Monogonosity

brute force, dp, math

Rollbacks (Easy Version)

brute force, data structures, dfs and similar, trees

Trees and Segments

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

Counting Graphs

combinatorics, divide and conquer, dsu, graphs, greedy, sortings, trees

More Wrong

divide and conquer, interactive

Expected Destruction

combinatorics, dp, math, probabilities

Earn or Unlock

bitmasks, brute force, dp

Ina of the Mountain

data structures, dp, greedy, math

Vlad and the Mountains

binary search, data structures, dsu, graphs, implementation, sortings, trees, two pointers

Max to the Right of Min

binary search, data structures, divide and conquer, dp, dsu, two pointers

Vika and Wiki

binary search, bitmasks, combinatorics, divide and conquer, dp, math

Vika and Bonuses

binary search, brute force, math, ternary search

The Boss's Identity

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

Boxes and Balls

dp, implementation, math

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

Tenzing and Tree

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

Tenzing and Triangle

data structures, dp, geometry, greedy, math

Fill the Matrix

data structures, greedy, math

Pairs of Segments

data structures, greedy, sortings, two pointers

In Search of Truth (Hard Version)

constructive algorithms, interactive, math, meet-in-the-middle, probabilities

In Search of Truth (Easy Version)

constructive algorithms, interactive, math, meet-in-the-middle, probabilities

Railguns

brute force, dfs and similar, dp, graphs

Decreasing Game

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

Ball Sorting

data structures, dp, sortings

Count Supersequences

combinatorics, dp, math