The Good Array

greedy, implementation, math

Count Supersequences

combinatorics, dp, math

No Prime Differences

constructive algorithms, math, number theory

Minimize Permutation Subarrays

constructive algorithms, math

Blackboard List

constructive algorithms, math

Grasshopper on a Line

constructive algorithms, math

Astrophysicists

greedy, math

Doctor's Brown Hypothesis

dfs and similar, graphs, math, number theory

Twin Clusters

bitmasks, brute force, constructive algorithms, math, probabilities

Lottery

binary search, brute force, greedy, math, two pointers

k-th equality

brute force, implementation, math

Typewriter

brute force, math

MEX of LCM

binary search, data structures, implementation, math, number theory

Game with Reversing

games, greedy, math, strings

Maximum Strength

greedy, math

Unit Array

greedy, math

Ira and Flamenco

combinatorics, constructive algorithms, data structures, implementation, math, sortings, two pointers

Vlad Building Beautiful Array

greedy, math

Red-Blue Operations (Hard Version)

binary search, constructive algorithms, greedy, implementation, math

Red-Blue Operations (Easy Version)

binary search, greedy, implementation, math

Bully Sort

data structures, math

Hyperregular Bracket Strings

combinatorics, greedy, hashing, math, number theory, sortings

The BOSS Can Count Pairs

brute force, math

Don't Blame Me

bitmasks, combinatorics, dp, math

Hits Different

data structures, dp, implementation, math

Forever Winter

dfs and similar, graphs, math

Permutation Swap

math, number theory

Divisible Array

constructive algorithms, math

Counting Orders

combinatorics, math, sortings, two pointers

Fading into Fog

geometry, interactive, math, probabilities

Dreaming of Freedom

greedy, math, number theory

Lunatic Never Content

math, number theory

LuoTianyi and the Table

greedy, math

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

Removing Graph

brute force, dp, games, graphs, math

Unique Palindromes

constructive algorithms, math, strings

Strongly Composite

greedy, math, number theory

Sort with Step

brute force, math, sortings

A-characteristic

combinatorics, constructive algorithms, math

Magic Triples (Hard Version)

brute force, data structures, math, number theory

Magic Triples (Easy Version)

brute force, data structures, math, number theory

Making Anti-Palindromes

greedy, math, strings

Super-Permutation

constructive algorithms, math

Bun Lover

math

Karina and Array

greedy, math, sortings

Timber

combinatorics, dp, fft, math

Black Cells

binary search, brute force, greedy, math

Tear It Apart

brute force, implementation, math, strings

Matching

combinatorics, math

JoJo's Incredible Adventures

math, strings, two pointers

Roads in E City

interactive, math, probabilities, trees

The Fox and the Complete Tree Traversal

constructive algorithms, dp, implementation, math, trees

Similar Polynomials

combinatorics, math

OH NO1 (-2-3-4)

constructive algorithms, graphs, math

Bosco and Particle

dp, math, number theory, strings

XOR Counting

bitmasks, combinatorics, dp, math

Ian and Array Sorting

greedy, math

Balancing Weapons

binary search, brute force, data structures, math, two pointers

Long Legs

brute force, math

Coins

implementation, math

Not a Geometry Problem

*special problem, *special problem, constructive algorithms, geometry, math

Trivial Conjecture

*special problem, constructive algorithms, math, number theory

Vlad and the Nice Paths (hard version)

binary search, combinatorics, data structures, dp, math, two pointers

Vlad and the Nice Paths (easy version)

combinatorics, dp, math

Living Sequence

binary search, dp, math, number theory

Umka and a Long Flight

constructive algorithms, implementation, math

Conveyor Belts

implementation, math

Insert Digit

greedy, math, strings

Last Number

combinatorics, math

M-tree

data structures, math, sortings, trees

Climbing the Tree

binary search, math

Candies

constructive algorithms, math, number theory

Prediction

combinatorics, dp, math

Two Tanks

binary search, dp, implementation, math

Sum on Subarrays

constructive algorithms, greedy, math

Points on Plane

binary search, greedy, math

Minibuses on Venus (hard version)

brute force, combinatorics, dp, math

Playing in a Casino

math, sortings

GCD Master (hard version)

greedy, math, sortings

GCD Master (easy version)

greedy, math, number theory, sortings

DSU Master

combinatorics, dp, dsu, math

Sequence Master

brute force, constructive algorithms, math

Walking Master

geometry, greedy, math

Survival of the Weakest (hard version)

greedy, math, sortings, two pointers

Survival of the Weakest (easy version)

binary search, brute force, implementation, math, sortings

Place for a Selfie

binary search, data structures, geometry, math

Pull Your Luck

brute force, greedy, math, number theory

Lame King

greedy, math

Settlement of Guinea Pigs

greedy, implementation, math

Another n-dimensional chocolate bar

dp, math, meet-in-the-middle, number theory

Count Voting

combinatorics, dp, math

City Union

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

Equalize by Divide

brute force, constructive algorithms, greedy, math

Recent Actions

data structures, greedy, implementation, math

Gifts from Grandfather Ahmed

dp, math, number theory

Shocking Arrangement

constructive algorithms, greedy, math

Candy Store

greedy, math, number theory

Li Hua and Array

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