Message Transmission Error (hard version)

hashing, string suffix structures, strings, two pointers

Yunli's Subarray Queries (easy version)

binary search, data structures, two pointers

Eri and Expanded Sets

data structures, divide and conquer, math, number theory, two pointers

Turtle and Three Sequences

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

Turtle and Inversions (Hard Version)

brute force, data structures, divide and conquer, dp, greedy, math, two pointers

Right Left Wrong

greedy, implementation, two pointers

Seating in a Bus

two pointers

Make Three Regions

constructive algorithms, two pointers

Let Me Teach You a Lesson (Hard Version)

data structures, dp, matrices, two pointers

Let Me Teach You a Lesson (Easy Version)

2-sat, data structures, dp, matrices, two pointers

Bouquet (Hard Version)

binary search, data structures, greedy, math, sortings, two pointers

Bouquet (Easy Version)

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

Hungry Games

binary search, dp, two pointers

Valuable Cards

brute force, dp, greedy, number theory, two pointers

Polygonal Segments

brute force, data structures, divide and conquer, dp, greedy, two pointers

Smithing Skill

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

Mathematical Problem

brute force, dp, greedy, implementation, math, two pointers

array-value

binary search, bitmasks, data structures, greedy, two pointers

Boring Day

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

Manhattan Triangle

binary search, constructive algorithms, data structures, geometry, implementation, two pointers

Large Graph

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

Invertible Bracket Sequences

binary search, combinatorics, data structures, divide and conquer, implementation, two pointers

Job Interview

binary search, dp, greedy, implementation, two pointers

Cutting Game

binary search, brute force, data structures, implementation, sortings, two pointers

Cat, Fox and the Lonely Array

binary search, bitmasks, data structures, greedy, math, two pointers

Contest Proposal

brute force, greedy, two pointers

Prefiquence

greedy, two pointers

Long Way to be Non-decreasing

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

Inaccurate Subsequence Search

data structures, two pointers

Amanda the Amoeba

graphs, implementation, trees, two pointers

Tandem Repeats?

brute force, strings, two pointers

MEX Game 2 (Hard Version)

binary search, greedy, two pointers

Rudolf and Imbalance

binary search, greedy, sortings, two pointers

Rudolf and k Bridges

binary search, data structures, dp, two pointers

More Gifts

*special problem, dfs and similar, two pointers

Bitwise Paradox

binary search, bitmasks, data structures, greedy, two pointers

Pinball

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

LR-remainders

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

Equalize

binary search, greedy, sortings, two pointers

Klever Permutation

constructive algorithms, math, two pointers

Find the Different Ones!

binary search, brute force, data structures, dp, dsu, greedy, two pointers

Slimes

binary search, constructive algorithms, data structures, greedy, two pointers

Very Different Array

data structures, greedy, sortings, two pointers

Blocking Elements

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

Innovative Washing Machine

geometry, math, two pointers

Cyclic MEX

data structures, implementation, math, two pointers

Array Game

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

Collecting Game

binary search, dp, greedy, sortings, two pointers

Landscaping

binary search, geometry, two pointers

Unusual Entertainment

data structures, dfs and similar, dsu, shortest paths, sortings, trees, two pointers

Yarik and Array

dp, greedy, two pointers

Sofia and Strings

data structures, greedy, sortings, strings, two pointers

Ones and Twos

binary search, data structures, divide and conquer, math, two pointers

AB Flipping

greedy, strings, two pointers

Infinite Card Game

binary search, brute force, data structures, dfs and similar, dp, dsu, games, graphs, greedy, sortings, two pointers

Neutral Tonality

constructive algorithms, greedy, sortings, two pointers

Smilo and Monsters

binary search, constructive algorithms, greedy, sortings, two pointers

Split

binary search, data structures, divide and conquer, dsu, math, trees, two pointers

Minimum Array

binary search, brute force, constructive algorithms, data structures, greedy, hashing, two pointers

I Wanna be the Team Leader

bitmasks, constructive algorithms, dp, greedy, math, sortings, two pointers

Haunted House

binary search, greedy, math, two pointers

Dances (Hard Version)

binary search, greedy, sortings, two pointers

Dances (Easy version)

binary search, greedy, two pointers

Lexichromatography

combinatorics, dfs and similar, dsu, graphs, two pointers

Money Trees

binary search, greedy, math, two pointers

1D Eraser

greedy, implementation, two pointers

Colorful Table

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

Imagination Castle

dp, games, two pointers

Speedrun

brute force, dfs and similar, dp, graphs, greedy, math, sortings, two pointers

Trees and Segments

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

Imbalanced Arrays

constructive algorithms, graphs, greedy, math, sortings, two pointers

Vlad and the Mountains

binary search, data structures, dsu, graphs, implementation, sortings, trees, two pointers

Parity Sort

greedy, sortings, two pointers

Max to the Right of Min

binary search, data structures, divide and conquer, dp, dsu, two pointers

Array Painting

constructive algorithms, greedy, two pointers

Hamon Odyssey

bitmasks, greedy, two pointers

Rating System

binary search, brute force, data structures, dp, dsu, greedy, math, two pointers

Tracking Segments

binary search, brute force, data structures, two pointers

Long Long

greedy, math, two pointers

Sasha and Array Coloring

greedy, sortings, two pointers

Monocarp and a Strategic Game

geometry, sortings, two pointers

Pairs of Segments

data structures, greedy, sortings, two pointers

Ski Resort

combinatorics, math, two pointers

Cipher Shifer

implementation, strings, two pointers

Lottery

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

Ira and Flamenco

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

Maximum Sum

brute force, sortings, two pointers

Range Sorting (Easy Version)

binary search, dp, dsu, greedy, trees, two pointers

Counting Orders

combinatorics, math, sortings, two pointers

JoJo's Incredible Adventures

math, strings, two pointers

Misha and Apples

brute force, data structures, dp, two pointers

The Butcher

geometry, greedy, implementation, sortings, two pointers

Balancing Weapons

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

Vlad and the Nice Paths (hard version)

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

Petya, Petya, Petr, and Palindromes

binary search, brute force, data structures, two pointers

Survival of the Weakest (hard version)

greedy, math, sortings, two pointers

There Should Be a Lot of Maximums

brute force, data structures, dfs and similar, dp, trees, two pointers

Li Hua and Array

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

Maximum Subarray

data structures, dp, greedy, two pointers

Scoring Subsequences

binary search, greedy, math, two pointers