Coloring a Red Black Tree

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

Interval Game

bitmasks, combinatorics, constructive algorithms, dp, games, games, greedy, greedy, math, probabilities

Operation Permutation

combinatorics, dp, math, probabilities

Fish Fight

dp, dp, math, probabilities, probabilities

Prufer Vertex

combinatorics, dsu, number theory, probabilities, trees

Jinx or Jackpot

brute force, dp, math, probabilities

Control Car (Hard Version)

combinatorics, dp, matrices, probabilities

Control Car (Easy Version)

combinatorics, dp, probabilities

deCH OR Dations

bitmasks, data structures, dp, hashing, probabilities

Beautiful Patterns (Hard Version)

combinatorics, math, probabilities

Beautiful Patterns (Easy Version)

combinatorics, math, probabilities

Shiro's Mirror Duel

constructive algorithms, greedy, interactive, probabilities, sortings

Beautiful Tree

constructive algorithms, math, probabilities, trees

Isaac's Queries

bitmasks, brute force, constructive algorithms, dfs and similar, divide and conquer, dp, greedy, interactive, math, probabilities

Hidden Single (Version 2)

binary search, divide and conquer, interactive, math, probabilities

Hidden Single (Version 1)

divide and conquer, interactive, math, probabilities, sortings

Buratsuta 3

binary search, brute force, data structures, divide and conquer, probabilities

Prime Gaming (Hard Version)

bitmasks, combinatorics, dp, probabilities

23 Rises Again

brute force, dfs and similar, dp, flows, graph matchings, graphs, greedy, implementation, probabilities, trees

Inter Active (Hard Version)

binary search, bitmasks, constructive algorithms, graphs, implementation, interactive, math, probabilities

Inter Active (Easy Version)

binary search, constructive algorithms, interactive, probabilities

Hamed and AghaBalaSar

brute force, combinatorics, dp, math, probabilities

Segments Covering

dp, math, probabilities

Gellyfish and Eternal Violet

combinatorics, dp, greedy, math, probabilities

Key of Like (Hard Version)

dp, math, probabilities

Key of Like (Easy Version)

dp, games, math, probabilities

Math Division

bitmasks, dp, math, probabilities

Empty Triangle

geometry, interactive, probabilities

XOR and Triangle

bitmasks, brute force, geometry, greedy, probabilities

LeaFall

combinatorics, dp, probabilities, trees

Condorcet Elections

constructive algorithms, graphs, greedy, probabilities

Control of Randomness

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

Penchick and Even Medians

binary search, constructive algorithms, interactive, probabilities

Alice's Adventures in the Rabbit Hole

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

Many Games

brute force, dp, greedy, math, probabilities

Expected Power

bitmasks, dp, math, probabilities

Turtle and Three Sequences

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

I Love Balls

combinatorics, math, probabilities

Arithmancy (Medium)

constructive algorithms, interactive, probabilities, strings

Frequency Mismatch (Hard Version)

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

Frequency Mismatch (Easy Version)

binary search, data structures, divide and conquer, hashing, probabilities, trees

Clacking Balls

combinatorics, math, probabilities

Grove

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

Rare Coins

combinatorics, math, probabilities

Good Trip

combinatorics, dp, math, probabilities

Paper Cutting Again

combinatorics, probabilities

ace5 and Task Order

constructive algorithms, divide and conquer, implementation, interactive, probabilities, sortings

Fugitive Frenzy

math, probabilities

Jellyfish and Miku

divide and conquer, dp, math, probabilities

Jellyfish and EVA

dp, graphs, greedy, math, probabilities

Mighty Rock Tower

brute force, combinatorics, dp, math, probabilities

Guess Game

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

Expected Destruction

combinatorics, dp, math, probabilities

Triangle Platinum?

brute force, combinatorics, implementation, interactive, math, probabilities

Tenzing and Random Real Numbers

bitmasks, dp, graphs, math, probabilities

Tenzing and Random Operations

combinatorics, dp, math, probabilities

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

Old Mobile

combinatorics, dp, probabilities

Twin Clusters

bitmasks, brute force, constructive algorithms, math, probabilities

Fading into Fog

geometry, interactive, math, probabilities

LuoTianyi and the Floating Islands (Hard Version)

combinatorics, dfs and similar, math, probabilities, trees

LuoTianyi and the Floating Islands (Easy Version)

combinatorics, math, probabilities, trees

Random Walk

dp, graphs, math, probabilities, trees

Roads in E City

interactive, math, probabilities, trees

Sum of Two Numbers

constructive algorithms, greedy, implementation, math, probabilities

Infinite Game

brute force, combinatorics, dp, games, probabilities

Flexible String Revisit

combinatorics, dp, math, probabilities

Score of a Tree

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

Game of Questions

bitmasks, combinatorics, dp, fft, math, probabilities

BinCoin

binary search, divide and conquer, hashing, implementation, probabilities, trees

Amazing Trick

constructive algorithms, graph matchings, math, probabilities

Hossam and Range Minimum Query

binary search, bitmasks, data structures, hashing, probabilities, strings, trees

Koxia and Tree

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

Guess the String

constructive algorithms, interactive, probabilities

Chemistry Lab

dp, geometry, probabilities

Card Guessing

combinatorics, dp, probabilities

Centroid Guess

interactive, probabilities, trees

Wish I Knew How to Sort

dp, math, probabilities

Kazaee

data structures, hashing, probabilities

Intersection and Union

data structures, dp, matrices, probabilities

Problem with Random Tests

brute force, dp, greedy, probabilities

Ela Goes Hiking

combinatorics, dp, math, probabilities

Guess the Cycle Size

interactive, probabilities

Edge Split

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

Tournament Countdown

constructive algorithms, greedy, interactive, number theory, probabilities

Mark and the Online Exam

bitmasks, constructive algorithms, interactive, probabilities

Expected Components

combinatorics, math, number theory, probabilities

A Random Code Problem

combinatorics, dp, math, number theory, probabilities

Robot Cleaner Revisit

implementation, math, probabilities

Messages

brute force, dp, greedy, probabilities, sortings

Party Organization

brute force, math, probabilities

Bubble Strike

combinatorics, math, probabilities, ternary search

The Mind

constructive algorithms, interactive, probabilities

Game of Chance

math, probabilities

Laser Beams

*special problem, geometry, probabilities

Tubular Bells

interactive, math, number theory, probabilities

DIY Tree

graphs, greedy, math, probabilities

Sports Betting

bitmasks, combinatorics, dp, graphs, math, probabilities

Need for Pink Slips

bitmasks, brute force, dfs and similar, implementation, math, probabilities