Neighbour Ordering

constructive algorithms, graphs

Two Avenues

data structures, dfs and similar, graphs

Dušan's Railway

divide and conquer, graphs, trees

Trains and Airplanes

dfs and similar, graphs, shortest paths, trees

Balance the Cards

constructive algorithms, data structures, divide and conquer, geometry, graphs, implementation

Stock Exchange

binary search, flows, graphs

Lost Nodes

constructive algorithms, dp, graphs, interactive, sortings, trees

Jumping Through the Array

binary search, data structures, graphs, two pointers

New Year and Snowy Grid

dfs and similar, dsu, graphs, interactive

Journey

data structures, divide and conquer, graphs, trees

JYPnation

graphs

Just Add an Edge

dfs and similar, dp, graphs

Kuroni and Antihype

bitmasks, brute force, dp, dsu, graphs

Railway Construction

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

Red-Blue Graph

dp, graphs, math, matrices, meet-in-the-middle

Harder Satisfiability

2-sat, dfs and similar, graphs

Fake bullions

combinatorics, dfs and similar, dp, graphs, number theory

Gregor and the Two Painters

data structures, divide and conquer, graphs, greedy, math

Swiper, no swiping!

graphs, implementation

Tree

fft, graphs, trees

Island Puzzle

dfs and similar, dsu, graphs, trees

Making It Bipartite

flows, graph matchings, graphs, number theory

Complete the Permutations

combinatorics, fft, graphs, math

Can Bash Save the Day?

data structures, divide and conquer, graphs, trees

Dynamic Shortest Path

graphs, shortest paths

Hex Dyslexia

bitmasks, brute force, dp, graphs

Tanya is 5!

graph matchings, graphs, greedy, schedules

Seollal

graphs

Kevin and Grid

fft, graphs, math

DIY Tree

graphs, greedy, math, probabilities

One Billion Shades of Grey

flows, graphs

Finding satisfactory solutions

combinatorics, dp, graphs, greedy, math

Harry Vs Voldemort

dfs and similar, dp, graphs, trees

Squares

constructive algorithms, data structures, dp, graphs, trees

Gold Experience

constructive algorithms, graphs, math, number theory, probabilities

Matvey's Birthday

bitmasks, graphs

Starry Night Camping

constructive algorithms, flows, graphs

Oppa Funcan Style Remastered

graphs, math, number theory, shortest paths

Bear and Chemistry

data structures, dfs and similar, graphs, trees

Public Service

constructive algorithms, graphs, trees

Roads Orientation Problem

graphs

Planar Perimeter

constructive algorithms, graphs

Bimatching

graphs

Special Edges

flows, graphs

Cross Xor

constructive algorithms, graphs, math, matrices

Cycle Palindrome

constructive algorithms, graphs, math

Air Reform

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

Strange Permutation

binary search, combinatorics, data structures, dp, graphs, implementation, two pointers

Shifting Dominoes

data structures, geometry, graphs, trees

Dirty Arkady's Kitchen

data structures, dp, graphs, shortest paths

New Year and Social Network

data structures, graph matchings, graphs, math, trees

Invertation in Tournament

brute force, divide and conquer, graphs, math

Pink Floyd

graphs, interactive

Election Promises

games, graphs

ALT

data structures, flows, graphs, trees

New Year and Forgotten Tree

constructive algorithms, flows, graphs

Kyoya and Train

dp, fft, graphs, math, probabilities

Tourists

data structures, dfs and similar, graphs, trees

Distance Sum

graphs

Projectors

flows, graphs

Football

graphs

Graph Coloring

data structures, graphs, interactive

Perpetual Motion Machine

constructive algorithms, dp, graphs, implementation, math, trees

Four Vertices

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

Cow and Exercise

flows, graphs, shortest paths

String Transformation 2

bitmasks, dp, graphs, trees

Flip and Reverse

data structures, graphs, greedy

Cycling City

dfs and similar, graphs

Unusual Graph

*special problem, graphs

Alpha planetary system

constructive algorithms, graphs, shortest paths

Nastya and Bees

graphs, interactive, probabilities

Spider

geometry, graphs

Gnomes of Might and Magic

data structures, graphs, implementation, shortest paths

Knightmare (hard)

graphs, interactive, shortest paths

Tree and Permutation Game

dfs and similar, games, graphs, trees

Alice and the Cactus

dfs and similar, graphs, math, probabilities

Maximum Flow

flows, graphs

Planar Graph

flows, geometry, graphs

Privatization

flows, graphs

Wizards and Roads

data structures, divide and conquer, graph matchings, graphs, greedy

Palindromic Hamiltonian Path

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

Reindeer Games

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

Down Below

binary search, dfs and similar, graphs, greedy, meet-in-the-middle, shortest paths

Mike and code of a permutation

constructive algorithms, data structures, graphs, sortings

Around the World

bitmasks, combinatorics, dfs and similar, dp, graphs, graphs, math, trees

Mashtali: a Space Oddysey

constructive algorithms, dfs and similar, graphs

Graph Game

graphs

James and the Chase

dfs and similar, graphs, probabilities, trees

Falling Sand (Hard Version)

dfs and similar, dp, graphs, greedy

Coffee Varieties (hard version)

constructive algorithms, graphs, interactive

Indecisive Taxi Fee

data structures, graphs, shortest paths

Abandoning Roads

brute force, dp, graphs, greedy

Points and Segments

graphs

The Classic Problem

data structures, graphs, shortest paths

Sergey's problem

constructive algorithms, graphs

Linearization

graphs

Deja Vu

constructive algorithms, graphs, implementation

Knightmare (easy)

graphs, interactive, shortest paths

Restore the Tree

graphs, greedy, trees

Cactus to Tree

dp, graphs, trees