Counting Is Not Fun (Hard Version)

binary search, combinatorics, data structures, dfs and similar, dsu, trees

Counting Is Not Fun (Easy Version)

combinatorics, data structures, dfs and similar, dp, dsu, implementation, math

Triangle Tree

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

Kevin and Teams

2-sat, binary search, bitmasks, brute force, chinese remainder theorem, combinatorics, constructive algorithms, data structures, dfs and similar, divide and conquer, dp, dsu, expression parsing, fft, flows, games, geometry, graph matchings, graphs, greedy, hashing, implementation, interactive, math, matrices, meet-in-the-middle, number theory, probabilities, schedules, shortest paths, sortings, string suffix structures, strings, ternary search, trees, two pointers

Kevin and Binary String (Hard Version)

2-sat, binary search, bitmasks, brute force, chinese remainder theorem, combinatorics, constructive algorithms, data structures, dfs and similar, divide and conquer, dp, dsu, expression parsing, fft, flows, games, geometry, graph matchings, graphs, greedy, hashing, implementation, interactive, math, matrices, meet-in-the-middle, number theory, probabilities, schedules, shortest paths, sortings, string suffix structures, strings, ternary search, trees, two pointers

Kevin and Binary String (Easy Version)

2-sat, binary search, bitmasks, brute force, chinese remainder theorem, combinatorics, constructive algorithms, data structures, dfs and similar, divide and conquer, dp, dsu, expression parsing, fft, flows, games, geometry, graph matchings, graphs, greedy, hashing, implementation, interactive, math, matrices, meet-in-the-middle, number theory, probabilities, schedules, shortest paths, sortings, string suffix structures, strings, ternary search, trees, two pointers

Kevin and And

2-sat, binary search, bitmasks, brute force, chinese remainder theorem, combinatorics, constructive algorithms, data structures, dfs and similar, divide and conquer, dp, dsu, expression parsing, fft, flows, games, geometry, graph matchings, graphs, greedy, hashing, implementation, interactive, math, matrices, meet-in-the-middle, number theory, probabilities, schedules, shortest paths, sortings, string suffix structures, strings, ternary search, trees, two pointers

Kevin and Numbers

2-sat, binary search, bitmasks, brute force, chinese remainder theorem, combinatorics, constructive algorithms, data structures, dfs and similar, divide and conquer, dp, dsu, expression parsing, fft, flows, games, geometry, graph matchings, graphs, greedy, hashing, implementation, interactive, math, matrices, meet-in-the-middle, number theory, probabilities, schedules, shortest paths, sortings, string suffix structures, strings, ternary search, trees, two pointers

Kevin and Puzzle

2-sat, binary search, bitmasks, brute force, chinese remainder theorem, combinatorics, constructive algorithms, data structures, dfs and similar, divide and conquer, dp, dsu, expression parsing, fft, flows, games, geometry, graph matchings, graphs, greedy, hashing, implementation, interactive, math, matrices, meet-in-the-middle, number theory, probabilities, schedules, shortest paths, sortings, string suffix structures, strings, ternary search, trees, two pointers

Kevin and Geometry

2-sat, binary search, bitmasks, brute force, chinese remainder theorem, combinatorics, constructive algorithms, data structures, dfs and similar, divide and conquer, dp, dsu, expression parsing, fft, flows, games, geometry, graph matchings, graphs, greedy, hashing, implementation, interactive, math, matrices, meet-in-the-middle, number theory, probabilities, schedules, shortest paths, sortings, string suffix structures, strings, ternary search, trees, two pointers

Kevin and Arithmetic

2-sat, binary search, bitmasks, brute force, chinese remainder theorem, combinatorics, constructive algorithms, data structures, dfs and similar, divide and conquer, dp, dsu, expression parsing, fft, flows, games, geometry, graph matchings, graphs, greedy, hashing, implementation, interactive, math, matrices, meet-in-the-middle, number theory, probabilities, schedules, shortest paths, sortings, string suffix structures, strings, ternary search, trees, two pointers

Graph Composition

dfs and similar, dsu, graphs, greedy

Secret Message

constructive algorithms, dfs and similar, math

Another Exercise on Graphs (hard version)

binary search, dfs and similar, dp, dsu, graphs, shortest paths, sortings

Nested Segments

combinatorics, dfs and similar, dp, dsu, math

Find the Permutation

brute force, dfs and similar, graphs, implementation, sortings

Resourceful Caterpillar Sequence

dfs and similar, dp, games, graphs, greedy, trees

Tree Destruction

dfs and similar, dp, trees

Mirror Maze

brute force, dfs and similar, graphs, implementation

Medium Demon Problem (hard version)

dfs and similar, dp, dsu, graphs, implementation, trees

Medium Demon Problem (easy version)

dfs and similar, graph matchings, graphs, implementation, trees

Matrix Transformation

bitmasks, brute force, data structures, dfs and similar, graphs, greedy, implementation

Vertex Pairs

binary search, brute force, data structures, dfs and similar, divide and conquer, greedy, implementation, trees

Trophic Balance Species

binary search, brute force, dfs and similar, graphs

Segmentation Folds

brute force, dfs and similar, number theory

Drunken Maze

brute force, dfs and similar, graphs, shortest paths

Cube

bitmasks, dfs and similar, dp

Control of Randomness

combinatorics, dfs and similar, dp, graphs, greedy, math, probabilities, trees

Non Prime Tree

brute force, constructive algorithms, dfs and similar, greedy, number theory, trees, two pointers

Tree Operations

binary search, brute force, dfs and similar, dp, trees

Rayan vs. Rayaneh

brute force, dfs and similar, dp, number theory

Trapped in the Witch's Labyrinth

constructive algorithms, dfs and similar, graphs, implementation

Sakurako and Chefir

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

Sakurako, Kosuke, and the Permutation

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

Penchick and Chloe's Trees

data structures, dfs and similar, dp, greedy, implementation, math, sortings, trees

Penchick and Desert Rabbit

binary search, data structures, dfs and similar, dp, dsu, greedy, implementation, two pointers

Cool Graph

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

Alice's Adventures in the Rabbit Hole

combinatorics, dfs and similar, dp, games, greedy, math, probabilities, trees

Add Zeros

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

Bermart Ice Cream

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

Best Subsequence

bitmasks, dfs and similar, flows, graph matchings, graphs

Choose Your Queries

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

C+K+S

constructive algorithms, dfs and similar, graphs, greedy, hashing, implementation, strings

Billetes MX (Easy Version)

2-sat, binary search, combinatorics, constructive algorithms, dfs and similar, dsu, graphs

Digital Village (Extreme Version)

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

Digital Village (Easy Version)

brute force, data structures, dfs and similar, dp, dsu, fft, graphs, greedy, implementation, math, trees

Tree Pruning

brute force, dfs and similar, greedy, sortings, trees

Sheriff's Defense

dfs and similar, dp, greedy, trees

Rendez-vous de Marian et Robin

dfs and similar, graphs, shortest paths

Iris's Full Binary Tree

brute force, data structures, dfs and similar, trees

Iris and the Tree

brute force, data structures, dfs and similar, dsu, math, trees

Iris and Game on the Tree

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

Turtle and a MEX Problem (Hard Version)

dfs and similar, dp, graphs, greedy, implementation, math

Court Blue (Easy Version)

brute force, dfs and similar, dp, math, number theory

DFS Checker (Hard Version)

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

DFS Checker (Easy Version)

brute force, data structures, dfs and similar, graphs, hashing, trees

Guess The Tree

binary search, brute force, dfs and similar, divide and conquer, dsu, greedy, interactive, trees

Maximize the Root

binary search, dfs and similar, dp, greedy, trees

Stardew Valley

constructive algorithms, dfs and similar, graphs, trees

Coloring Game

constructive algorithms, dfs and similar, games, graphs, greedy, interactive

Catch the Mole(Hard Version)

binary search, data structures, dfs and similar, divide and conquer, interactive, trees

Catch the Mole(Easy Version)

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

Simultaneous Coloring

dfs and similar, divide and conquer, graphs

The Omnipotent Monster Killer

brute force, dfs and similar, dp, trees

Wonderful Tree!

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

Non-academic Problem

dfs and similar, graphs, trees

Maximize the Largest Component (Hard Version)

data structures, dfs and similar, dp, dsu, implementation

Maximize the Largest Component (Easy Version)

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

Turtle and Multiplication

constructive algorithms, dfs and similar, graphs, number theory

Yasya and the Mysterious Tree

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

Large Graph

data structures, dfs and similar, dsu, graphs, number theory, two pointers

Remove Bridges

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

Splittable Permutations

combinatorics, data structures, dfs and similar, greedy, math, trees

Set

bitmasks, brute force, combinatorics, dfs and similar, divide and conquer, dp, math

Chain Queries

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

Paint the Tree

brute force, dfs and similar, dp, greedy, shortest paths, trees

±1

2-sat, dfs and similar, graphs

Circle Perimeter

binary search, brute force, dfs and similar, geometry, implementation, math

Min-Fund Prison (Hard)

bitmasks, dfs and similar, dp, graphs, trees

Min-Fund Prison (Medium)

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

Min-Fund Prison (Easy)

dfs and similar, trees

Game on Tree (Hard)

dfs and similar, dp, games, trees

Game on Tree (Medium)

dfs and similar, dp, games, trees

Permutation Game

brute force, dfs and similar, games, graphs, greedy, math

Long Way to be Non-decreasing

binary search, dfs and similar, graphs, implementation, shortest paths, two pointers

Frequency Mismatch (Hard Version)

binary search, data structures, dfs and similar, hashing, probabilities, trees

GCD on a grid

brute force, dfs and similar, dp, implementation, math, number theory

Mathematician Takeover

binary search, dfs and similar, math

Shuffling Songs

bitmasks, dfs and similar, dp, graphs, hashing, implementation, strings

Disks

dfs and similar, geometry, graph matchings, graphs

Annual Ants' Gathering

dfs and similar, dp, greedy, trees

Grove

brute force, dfs and similar, dp, geometry, probabilities

Arrow Path

brute force, constructive algorithms, dfs and similar, dp, graphs, shortest paths

Nobody is needed

2-sat, data structures, dfs and similar, dp

Tree Compass

constructive algorithms, dfs and similar, greedy, trees

Learning to Paint

binary search, data structures, dfs and similar, dp, greedy, implementation, sortings

Rudolf and Subway

constructive algorithms, dfs and similar, graphs, shortest paths

Rudolf and the Ball Game

dfs and similar, dp, implementation

Burenka and Pether

*special problem, data structures, dfs and similar, divide and conquer, dsu, graphs, sortings, trees

Parallel Universes

*special problem, constructive algorithms, dfs and similar, dsu, graphs