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

Tree Array

brute force, combinatorics, dp, graphs, math, probabilities, trees

Bingo

bitmasks, combinatorics, dp, math, probabilities

Median Queries

constructive algorithms, interactive, probabilities

Assimilation IV

combinatorics, dp, math, probabilities, two pointers

Crypto Lights

combinatorics, dp, math, probabilities

Love-Hate

bitmasks, brute force, dp, probabilities

Is It Rated?

greedy, interactive, math, probabilities

School Clubs

dp, fft, math, number theory, probabilities

Odd Mineral Resource

binary search, bitmasks, brute force, data structures, probabilities, trees

Nezzar and Chocolate Bars

combinatorics, fft, math, probabilities

Random Events

dp, math, probabilities

Red-Blue Shuffle

math, probabilities

Special Permutation

constructive algorithms, probabilities

Checkpoints

brute force, constructive algorithms, greedy, math, probabilities

Olha and Igor

interactive, probabilities, trees

Expected Damage

binary search, combinatorics, probabilities

ZS Shuffles Cards

combinatorics, dp, math, probabilities

Circular Dungeon

greedy, math, probabilities

X-OR

bitmasks, constructive algorithms, divide and conquer, interactive, probabilities

James and the Chase

dfs and similar, graphs, probabilities, trees

Find a Gift

binary search, interactive, probabilities

Slime and Biscuits

math, probabilities

Nastya and Bees

graphs, interactive, probabilities

Battalion Strength

data structures, divide and conquer, probabilities

Tourism

dp, graphs, probabilities

Kuroni and the Punishment

math, number theory, probabilities

Good Contest

combinatorics, dp, probabilities

LCC

data structures, math, matrices, probabilities

Santa's Bot

combinatorics, math, probabilities

Cards

combinatorics, dp, math, number theory, probabilities

Game Relics

math, probabilities

Beautiful Mirrors

data structures, dp, math, probabilities

Beautiful Bracket Sequence (hard version)

combinatorics, probabilities

Beautiful Bracket Sequence (easy version)

combinatorics, dp, probabilities

Beautiful Mirrors with queries

data structures, probabilities

Tree Queries

data structures, probabilities, trees

Hyakugoku and Ladders

dp, probabilities, shortest paths