Chips on a Board

bitmasks, brute force, data structures, games, two pointers

Flip the Cards

2-sat, constructive algorithms, data structures, greedy, sortings, two pointers

Travelling Salesman Problem

binary search, data structures, dp, greedy, shortest paths, sortings, two pointers

Square-free division (hard version)

data structures, dp, greedy, math, number theory, two pointers

Square-free division (easy version)

data structures, dp, greedy, math, number theory, two pointers

Tiles for Bathroom

data structures, sortings, two pointers

Matrix Sorting

bitmasks, brute force, constructive algorithms, greedy, two pointers

Enormous XOR

bitmasks, constructive algorithms, greedy, math, strings, two pointers

GCD of an Array

brute force, data structures, hashing, implementation, math, number theory, sortings, two pointers

1D Sokoban

binary search, dp, greedy, implementation, two pointers

Maximum width

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

Cheap Dinner

brute force, data structures, graphs, greedy, implementation, sortings, two pointers

Minimum Difference

data structures, hashing, sortings, two pointers

Cleaning the Phone

binary search, dp, sortings, two pointers

Strange Permutation

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

Strange Birthday Party

binary search, dp, greedy, sortings, two pointers

Correct Placement

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

A Bit Similar

bitmasks, brute force, hashing, string suffix structures, strings, two pointers

Building a Fence

dp, greedy, implementation, two pointers

Pairs

binary search, constructive algorithms, greedy, two pointers

Close Tuples (hard version)

binary search, combinatorics, implementation, math, sortings, two pointers

Close Tuples (easy version)

binary search, combinatorics, math, sortings, two pointers

Favorite Sequence

implementation, two pointers

Rating Compression

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

Array Partition

binary search, data structures, greedy, two pointers

Two Editorials

brute force, dp, greedy, sortings, two pointers

Frequency Problem (Hard Version)

data structures, greedy, two pointers

Rogue-like Game

*special problem, brute force, greedy, two pointers

Polycarp and the Language of Gods

*special problem, implementation, two pointers

Yurii Can Do Everything

binary search, bitmasks, brute force, constructive algorithms, divide and conquer, two pointers

Long Permutation

brute force, math, two pointers

Emotional Fishermen

combinatorics, dp, math, two pointers

Perform Easily

binary search, brute force, dp, implementation, sortings, two pointers

Complicated Computations

binary search, data structures, two pointers

Fruit Sequences

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

String Deletion

binary search, data structures, greedy, two pointers

Lonely Numbers

binary search, math, number theory, two pointers

Searchlights

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

Discrete Acceleration

binary search, dp, implementation, math, two pointers

k-Amazing Numbers

binary search, data structures, implementation, two pointers

Sage's Birthday (hard version)

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

Three Occurrences

data structures, divide and conquer, hashing, two pointers

Equal Product

data structures, math, number theory, two pointers

Chocolate Bunny

constructive algorithms, interactive, math, two pointers

Fixed Point Removal

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

Two Platforms

binary search, dp, sortings, two pointers

Rainbow Rectangles

data structures, sortings, two pointers

The Potion of Great Power

*special problem, 2-sat, binary search, data structures, graphs, interactive, sortings, two pointers

Mercenaries

bitmasks, brute force, combinatorics, dp, dsu, math, two pointers

Zigzags

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

Controversial Rounds

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

Boboniu Chats with Du

dp, greedy, sortings, two pointers

Twilight and Ancient Scroll (harder version)

dp, hashing, implementation, string suffix structures, strings, two pointers

Weights Division (hard version)

binary search, dfs and similar, greedy, sortings, trees, two pointers

Boats Competition

brute force, greedy, two pointers

Good String

brute force, dp, greedy, two pointers

String Transformation 1

dsu, graphs, greedy, sortings, strings, trees, two pointers

New Passenger Trams

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

Choosing flowers

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

The Majestic Brown Tree Snake

dfs and similar, dp, greedy, trees, two pointers

Mastermind

constructive algorithms, graph matchings, greedy, implementation, sortings, two pointers

Prefix Flip (Hard Version)

constructive algorithms, data structures, implementation, strings, two pointers

Berserk And Fireball

constructive algorithms, greedy, implementation, math, two pointers

Omkar and Last Floor

dp, greedy, two pointers

Reading Books (hard version)

data structures, greedy, implementation, sortings, ternary search, two pointers

Zero Remainder Array

math, sortings, two pointers

RationalLee

greedy, math, sortings, two pointers

Flying Sort (Hard Version)

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

Flying Sort (Easy Version)

dp, greedy, two pointers

XXXXX

brute force, data structures, number theory, two pointers

Most socially-distanced subsequence

greedy, two pointers

Two Arrays

binary search, brute force, combinatorics, constructive algorithms, dp, two pointers

Shuffle

math, two pointers

Yet Another Yet Another Task

data structures, dp, implementation, two pointers

New Theatre Square

brute force, dp, greedy, implementation, two pointers

The Best Vacation

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

Ternary String

binary search, dp, implementation, two pointers

Count Triangles

binary search, implementation, math, two pointers

Special Elements

brute force, implementation, two pointers

Multiple Testcases

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

Constant Palindrome Sum

brute force, data structures, greedy, two pointers

Alternating Subsequence

dp, greedy, two pointers

Xenia and Colorful Gems

binary search, greedy, math, sortings, two pointers

Three Blocks Palindrome (hard version)

brute force, data structures, dp, two pointers

Three Blocks Palindrome (easy version)

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

Kate and imperfection

greedy, implementation, math, number theory, sortings, two pointers

Eugene and an array

binary search, data structures, implementation, two pointers

AND Segments

bitmasks, combinatorics, data structures, dp, two pointers

Bombs

data structures, two pointers

Pair of Topics

binary search, data structures, sortings, two pointers

Attack on Red Kingdom

games, two pointers

Kuroni and Simple Strings

constructive algorithms, greedy, strings, two pointers

Concatenation with intersection

data structures, hashing, strings, two pointers

Shortest and Longest LIS

constructive algorithms, graphs, greedy, two pointers

Air Conditioner

dp, greedy, implementation, sortings, two pointers

Irreducible Anagrams

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

Delete a Segment

brute force, constructive algorithms, data structures, dp, graphs, sortings, trees, two pointers

Petya and Exam

greedy, sortings, two pointers

Decreasing Debts

constructive algorithms, data structures, graphs, greedy, implementation, math, two pointers

Two Bracket Sequences

dp, strings, two pointers