Multiple of Three Cycles

combinatorics, data structures, dp, dsu, math

Great Grids

2-sat, constructive algorithms, dfs and similar, dsu, graphs

Ksyusha and Chinchilla

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

Round Dance

dfs and similar, dsu, graphs, shortest paths

The Lakes

dfs and similar, dsu, graphs, implementation

Range Sorting (Easy Version)

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

LuoTianyi and XOR-Tree

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

Communication Towers

brute force, divide and conquer, dsu

Monsters

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

DSU Master

combinatorics, dp, dsu, math

Flow Control

data structures, dsu, implementation

Gasoline prices

data structures, divide and conquer, dsu, hashing, trees

Unforgivable Curse (hard version)

brute force, constructive algorithms, dfs and similar, dsu, graphs, greedy, strings

Unforgivable Curse (easy version)

brute force, constructive algorithms, dsu, graphs, greedy, strings

City Union

constructive algorithms, dfs and similar, dsu, geometry, greedy, implementation, math

Li Hua and Path

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

Li Hua and Array

brute force, data structures, dsu, math, number theory, two pointers

XOR, Tree, and Queries

bitmasks, constructive algorithms, dfs and similar, dsu, graphs, greedy, implementation, trees

Game on Axis

combinatorics, dfs and similar, dsu, graphs, implementation

Delicious Dessert

binary search, dsu, hashing, math, number theory, string suffix structures

Boris and His Amazing Haircut

constructive algorithms, data structures, dp, dsu, greedy, sortings

Koxia and Tree

combinatorics, dfs and similar, dp, dsu, math, probabilities, trees

Koxia and Game

constructive algorithms, data structures, dfs and similar, dsu, flows, games, graph matchings, graphs, implementation

Access Levels

bitmasks, dsu, flows, graph matchings

Doremy's Experimental Tree

brute force, constructive algorithms, dfs and similar, dsu, sortings, trees

Edge Queries

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

Make It Connected

binary search, brute force, constructive algorithms, dsu, graphs, greedy, matrices, trees, two pointers

Tick, Tock

combinatorics, dfs and similar, dsu, graphs

Dangerous Laser Power

constructive algorithms, dsu, sortings

Connectivity Addicts

constructive algorithms, dsu, graphs, greedy, interactive, shortest paths, trees

Permutation Addicts

constructive algorithms, data structures, dfs and similar, dsu, graphs, trees

Phase Shift

dfs and similar, dsu, graphs, greedy, implementation, strings

Edge Split

brute force, constructive algorithms, dfs and similar, dsu, graphs, probabilities, trees

Jatayu's Balanced Bracket Sequence

data structures, dsu, graphs, greedy

Kingdom of Criticism

data structures, dsu

Imitating the Key Tree

combinatorics, dsu, trees

Cross Swapping

2-sat, data structures, dsu, greedy, matrices

XOR Tree

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

DFS Trees

dfs and similar, dsu, graphs, greedy, sortings, trees

Qpwoeirut and Vertices

binary search, data structures, dfs and similar, divide and conquer, dsu, greedy, trees

Split Into Two Sets

dfs and similar, dsu, graphs

Tree Recovery

brute force, constructive algorithms, dfs and similar, dsu, graphs, trees

Number of Groups

data structures, dfs and similar, dsu, graphs, greedy, sortings

ANDfinity

bitmasks, brute force, constructive algorithms, dfs and similar, dsu, graphs

Cute number

binary search, brute force, data structures, dsu, implementation, math

Sanae and Giant Robot

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

Permutation Weight (Easy Version)

constructive algorithms, dfs and similar, dsu

Unique Occurrences

data structures, dfs and similar, divide and conquer, dp, dsu, trees

Lenient Vertex Cover

dfs and similar, divide and conquer, dsu, graphs, trees

Replace With the Previous, Minimize

dsu, greedy, strings

Preorder

combinatorics, divide and conquer, dp, dsu, hashing, sortings, trees

Where is the Pizza?

data structures, dfs and similar, dsu, graphs, implementation, math

Narrow Components

brute force, data structures, dp, dsu, math, trees

AND-MEX Walk

bitmasks, brute force, constructive algorithms, dfs and similar, dsu, graphs

Words on Tree

2-sat, dfs and similar, dsu, graphs, trees

Air Reform

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

Anonymity Is Important

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

Inversion Graph

data structures, dsu, graphs, math

Cars

2-sat, constructive algorithms, dfs and similar, dsu, graphs, greedy, sortings

Spanning Tree Queries

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

Groceries in Meteor Town

binary search, data structures, dsu, trees

MinOr Tree

bitmasks, dfs and similar, dsu, graphs, greedy

Replace the Numbers

constructive algorithms, data structures, dsu, implementation

Equal or Not Equal

constructive algorithms, dsu, implementation

Unusual Minesweeper

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

Trader Problem

data structures, dsu, greedy, sortings

X(or)-mas Tree

bitmasks, dfs and similar, dsu, graphs, trees

Social Network

dsu, graphs, greedy, implementation, trees

The Number of Imposters

constructive algorithms, dfs and similar, dp, dsu, graphs

Hemose Shopping

constructive algorithms, dsu, math, sortings

Labyrinth

binary search, dsu, greedy

Building Forest Trails

data structures, dsu

Jeopardy of Dropped Balls

binary search, brute force, dsu, implementation

Occurrences

combinatorics, dfs and similar, dp, dsu, fft, graphs

One-Four Overload

2-sat, constructive algorithms, dfs and similar, dsu, graphs, implementation

Mocha and Diana (Hard Version)

brute force, constructive algorithms, dfs and similar, dsu, graphs, greedy, trees, two pointers

Mocha and Diana (Easy Version)

brute force, constructive algorithms, dsu, graphs, greedy, trees

Gates to Another World

bitmasks, data structures, dsu, two pointers

Good Graph

data structures, dsu, graphs, trees

Common Divisor Graph

brute force, constructive algorithms, dsu, graphs, hashing, math, number theory

Permutation Shift

brute force, combinatorics, constructive algorithms, dfs and similar, dsu, graphs, math

Jumping Around

binary search, data structures, divide and conquer, dp, dsu, graphs, shortest paths

Figure Fixing

constructive algorithms, dfs and similar, dsu, graphs, greedy, math

Little Alawn's Puzzle

combinatorics, dp, dsu, graphs, math

Nastia Plays with a Tree

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

Phoenix and Earthquake

constructive algorithms, dfs and similar, dsu, graphs, greedy, trees

GCD and MST

constructive algorithms, dsu, graphs, greedy, number theory, sortings

Complete the MST

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

Dogeforces

constructive algorithms, data structures, dfs and similar, divide and conquer, dsu, greedy, sortings, trees

Playlist

data structures, dsu, implementation, shortest paths

Journey

dfs and similar, dp, dsu, implementation

Road Reform

dsu, graphs, greedy

Bakery

data structures, dsu

Euclid's nightmare

bitmasks, dfs and similar, dsu, graphs, greedy, math, sortings

Plan of Lectures

constructive algorithms, dfs and similar, dsu, graphs, implementation, sortings, trees

Team-Building

data structures, dfs and similar, dsu, graphs

Identify the Operations

combinatorics, data structures, dsu, greedy, implementation

A Convex Game

dsu, games

Virus

data structures, divide and conquer, dsu, graphs

Rain of Fire

binary search, data structures, dfs and similar, dsu, graphs, implementation