Maximum GCD Sum Queries

dp, implementation, number theory

Cat, Fox and Double Maximum

constructive algorithms, greedy, implementation, math, sortings

Chess For Three

brute force, implementation, math, math

Circle Perimeter

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

Binary Cut

dp, greedy, implementation, sortings, strings

Clock and Strings

implementation

Different String

implementation, strings

My First Sorting Problem

implementation, sortings

Playing Quidditch (Hard)

implementation

Playing Quidditch (Medium)

implementation

Playing Quidditch (Easy)

implementation

Balanced Shuffle (Easy)

implementation, sortings

Card Pairing

dp, greedy, hashing, implementation

Minimizing the Sum

dp, implementation

Two Friends

constructive algorithms, implementation, math

Next and Prev

brute force, data structures, implementation

Long Way to be Non-decreasing

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

Permutation Counting

binary search, greedy, implementation, math, sortings

Rectangle Filling

constructive algorithms, implementation

A BIT of a Construction

bitmasks, constructive algorithms, greedy, implementation

Nene vs. Monsters (Hard Version)

brute force, greedy, implementation, math

Nene vs. Monsters (Easy Version)

brute force, implementation, math

Nene and the Mex Operator

bitmasks, brute force, constructive algorithms, divide and conquer, dp, greedy, implementation, math

GCD on a grid

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

Long Inversions

brute force, greedy, implementation, sortings

Inhabitant of the Deep Sea

greedy, implementation, math

Progressive Square

constructive algorithms, data structures, implementation, sortings

Chain Reaction

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

Make It Ugly

implementation, math

Help, what does it mean to be "Based"

brute force, constructive algorithms, expression parsing, implementation, sortings

Palindrome

implementation, strings

Are You a Procrastinator?

implementation

No Palindromes

brute force, constructive algorithms, divide and conquer, greedy, hashing, implementation, math, strings

Shuffling Songs

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

0, 1, 2, Tree!

bitmasks, brute force, greedy, implementation, trees

Nearly Shortest Repeating Substring

brute force, implementation, number theory, strings

Product of Binary Decimals

brute force, dp, implementation, number theory

Clock Conversion

implementation, math

Upscaling

implementation

Stair, Peak, or Neither?

implementation

Amanda the Amoeba

graphs, implementation, trees, two pointers

Clique Partition

brute force, constructive algorithms, graphs, greedy, implementation

Array Fix

brute force, dp, greedy, implementation

Birthday Gift

bitmasks, brute force, constructive algorithms, greedy, implementation

Tree Cutting

binary search, dp, greedy, implementation, trees

Median of an Array

greedy, implementation, sortings

Cook and Porridge

binary search, constructive algorithms, data structures, implementation

Non-Palindromic Substring

hashing, implementation, math, strings

Farmer John's Favorite Function

brute force, data structures, implementation, math

Learning to Paint

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

Rudolf and the Ball Game

dfs and similar, dp, implementation

Three Arrays

*special problem, constructive algorithms, implementation, sortings

Binary Path

dp, greedy, implementation

Shuffle Party

implementation, math

Pokémon Arena

data structures, graphs, greedy, implementation, shortest paths, sortings

Pinball

binary search, data structures, implementation, math, two pointers

Andrey's Tree

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

Exam in MAC

binary search, combinatorics, implementation, math

Turtle vs. Rabbit Race: Optimal Trainings

binary search, implementation, math, ternary search

Turtle Fingers: Count the Values of k

brute force, implementation, math, number theory

Turtle Math: Fast Three Task

implementation, math, number theory

Final Countdown

implementation, math, number theory

Card Game

greedy, implementation

LR-remainders

brute force, data structures, implementation, math, two pointers

Thorns and Coins

dp, greedy, implementation

Sum over all Substrings (Hard Version)

bitmasks, divide and conquer, dp, dsu, greedy, implementation, strings

Digital Patterns

combinatorics, data structures, implementation, math

Microcycle

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

Vlad and Trouble at MIT

dfs and similar, dp, flows, graphs, greedy, implementation, trees

Vlad and Avoiding X

bitmasks, brute force, dfs and similar, dp, implementation

Vlad and an Odd Ordering

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

Vlad and a Sum of Sum of Digits

dp, implementation

Vlad and Shapes

geometry, implementation

Vlad and the Best of Five

implementation

Space Harbour

data structures, implementation, math, sortings

Shrink-Reverse

binary search, brute force, greedy, hashing, implementation, string suffix structures, strings

Monsters Attack!

dp, greedy, implementation

Moving Chips

greedy, implementation

Berserk Monsters

brute force, data structures, dsu, implementation, math

Closest Cities

greedy, implementation, math

Tricky Template

constructive algorithms, implementation, strings

Mischievous Shooter

brute force, data structures, divide and conquer, dp, implementation

Sum of Progression

brute force, data structures, dp, implementation, math

Arranging Cats

greedy, implementation

Array Repetition

binary search, brute force, dsu, implementation, math

Counting Prefixes

combinatorics, constructive algorithms, dp, implementation, math

Caterpillar on a Tree

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

ace5 and Task Order

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

Blocking Elements

binary search, data structures, dp, implementation, two pointers

XOR-distance

bitmasks, greedy, implementation, math

Minimize Inversions

constructive algorithms, data structures, greedy, implementation, sortings

Brick Wall

constructive algorithms, greedy, implementation, math

Yet Another Inversions Problem

combinatorics, data structures, dp, implementation, math, number theory

Watering an Array

brute force, greedy, implementation, math

Training Before the Olympiad

constructive algorithms, games, greedy, implementation, math

2023

constructive algorithms, implementation, math, number theory

Bicycles

graphs, greedy, implementation, shortest paths, sortings

Unnatural Language Processing

greedy, implementation, strings

Can I Square?

binary search, implementation

Not Quite Latin Square

bitmasks, brute force, implementation