Game of Pairs

constructive algorithms, dfs and similar, interactive, math, number theory

Fixed Point Removal

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

Tree Tag

dfs and similar, dp, games, trees

Balanced Bitstring

implementation, strings

Chess Rush

*special problem, combinatorics, dp, implementation, math

Spring cleaning

*special problem, data structures, dfs and similar, graphs, trees

The Potion of Great Power

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

Star Trek

*special problem, combinatorics, dfs and similar, dp, games, graphs, matrices, trees

Roads

*special problem, geometry, sortings

Fancy Fence

*special problem, data structures, dsu, implementation, math, sortings

Reverse and Swap

binary search, bitmasks, data structures

Divide Square

data structures, geometry, implementation, sortings

Maximum Distributed Tree

dfs and similar, dp, greedy, implementation, math, number theory, sortings, trees

Mercenaries

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

x-prime Substrings

brute force, dfs and similar, dp, string suffix structures, strings

Clear the Multiset

data structures, divide and conquer, dp, greedy

Zigzags

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

Binary String Reconstruction

2-sat, brute force, constructive algorithms, greedy

RPG Protagonist

brute force, greedy, math

Yet Another Segments Subset

data structures, dp, graphs, sortings

Weights Division (hard version)

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

Weights Division (easy version)

data structures, dfs and similar, greedy, trees

Binary String To Subsequences

constructive algorithms, data structures, greedy, implementation

Running Competition

bitmasks, fft, math, number theory

Controversial Rounds

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

Two Types of Spells

binary search, data structures, greedy, implementation, math, sortings

Colored Rectangles

dp, greedy, sortings

Good Subarrays

data structures, dp, math

Power Sequence

brute force, math, number theory, sortings

Distance Matching

constructive algorithms, dfs and similar, trees

Rainbow Rectangles

data structures, sortings, two pointers

Monster Invaders

dp, greedy, implementation

Stoned Game

brute force, constructive algorithms, games, greedy

Multiples of Length

constructive algorithms, greedy, number theory

Boboniu and Bit Operations

bitmasks, brute force, dp, greedy

Boboniu and Banknote Collection

strings

Boboniu and Jianghu

dp, greedy, sortings, trees

Boboniu and String

binary search, geometry, ternary search

Boboniu Walks on Graph

brute force, dfs and similar, graphs, hashing

Boboniu Chats with Du

dp, greedy, sortings, two pointers

Twilight and Ancient Scroll (harder version)

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

Twilight and Ancient Scroll (easier version)

dp, hashing, implementation, string suffix structures, strings

Rarity and New Dress

dfs and similar, dp, implementation, shortest paths

Pinkie Pie Eats Patty-cakes

constructive algorithms, greedy, math, sortings

Applejack and Storages

constructive algorithms, data structures, greedy, implementation

Kevin and Grid

fft, graphs, math

ZS Shuffles Cards

combinatorics, dp, math, probabilities

Omkar and Pies

bitmasks, dfs and similar, dp, math, shortest paths

Omkar and Landslide

binary search, constructive algorithms, data structures, greedy, math

Omkar and Duck

bitmasks, constructive algorithms, interactive, math

Omkar and Bed Wars

dp, greedy

Pairs of Pairs

constructive algorithms, dfs and similar, graphs, greedy, trees

505

bitmasks, brute force, constructive algorithms, dp, greedy, implementation

Cyclic Permutations

combinatorics, dp, graphs, math

Directing Edges

dfs and similar, dp, graphs, trees

Bicolored Segments

data structures, dp, graph matchings, sortings

Calendar Ambiguity

math, number theory

Segment Intersections

brute force, greedy, implementation, math

Good String

brute force, dp, greedy, two pointers

Array Walk

brute force, dp, greedy

Uncle Bogdan and Projections

data structures, geometry, sortings

Captain Flint and Treasure

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

Uncle Bogdan and Country Happiness

dfs and similar, greedy, math, trees

Viruses

*special problem, dp, shortest paths, string suffix structures

Village (Maximum)

*special problem, dfs and similar, trees

Village (Minimum)

*special problem, dp, greedy, trees

Graph

*special problem, binary search, dfs and similar, dp, math, ternary search

Joker

*special problem, bitmasks, data structures, divide and conquer, dsu

Mixture

*special problem, data structures, geometry, math, sortings

Colors

*special problem, binary search, constructive algorithms, interactive

Columns Swaps

2-sat, dfs and similar, dsu, graphs, implementation

Removing Leaves

data structures, greedy, implementation, trees

Directing Edges

constructive algorithms, dfs and similar, graphs

a-Good String

bitmasks, brute force, divide and conquer, dp, implementation

Koa and the Beach (Hard Version)

constructive algorithms, dp, greedy, implementation

Koa and the Beach (Easy Version)

brute force, dp, greedy

Special Edges

flows, graphs

Strange Operation

combinatorics, data structures, dp

Rearrange

brute force, constructive algorithms, graphs, greedy, sortings

String Transformation 2

bitmasks, dp, graphs, trees

GameGame

bitmasks, constructive algorithms, dp, games, greedy, math

String Transformation 1

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

Origami

geometry, math, sortings

The Majestic Brown Tree Snake

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

Mastermind

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

Unmerge

dp

Prefix Flip (Hard Version)

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

Circular Dungeon

greedy, math, probabilities

Strange Addition

data structures, dp, matrices

Merging Towers

data structures, dsu, implementation, trees

Berserk And Fireball

constructive algorithms, greedy, implementation, math, two pointers

Create The Teams

brute force, dp, greedy, implementation, sortings

Universal Solution

greedy

Chess Strikes Back (hard version)

data structures, divide and conquer

Chess Strikes Back (easy version)

binary search, data structures

Inverse Genealogy

constructive algorithms, divide and conquer, dp, math, trees

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

Dubious Cyrpto

binary search, brute force, math, number theory

Acacius and String

brute force, implementation, strings