Piet's Palette

matrices

Ants

2-sat, data structures, trees

Inverse Inversions

binary search, brute force, data structures

Vabank

binary search, interactive

Asterism Stream

dp, math, matrices

Tree Cutting

bitmasks, dfs and similar, dp

Cycle Palindrome

constructive algorithms, graphs, math

Line Distance

binary search, data structures, geometry

Split

binary search, data structures, dp, greedy

Listening to Music

constructive algorithms, data structures

Feeling Good

bitmasks, data structures

Sasha and Algorithm of Silence's Sounds

data structures, trees

Strange Permutation

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

A Game on Strings

games

Triameter

binary search, data structures, dfs and similar, trees

Sharti

data structures, games

Boring Card Game

data structures, greedy, trees

Pepe Racing

constructive algorithms, implementation, interactive, sortings

New Year and Social Network

data structures, graph matchings, graphs, math, trees

Cross Xor

constructive algorithms, graphs, math, matrices

Distance Matching

constructive algorithms, dfs and similar, trees

Special Edges

flows, graphs

The Sum of Good Numbers

hashing, math, string suffix structures, strings

Raining season

data structures, divide and conquer, trees

Mergesort Strikes Back

math, probabilities

Twilight and Ancient Scroll (harder version)

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

Teleportation in Byteland

data structures, dfs and similar, divide and conquer, graphs, shortest paths, trees

Segment Covering

brute force, combinatorics, constructive algorithms, data structures, dp, trees

Joking (Hard Version)

dp, interactive

Into Blocks (hard version)

data structures

Air Reform

data structures, dfs and similar, divide and conquer, dsu, graphs, implementation, trees

Dirty Arkady's Kitchen

data structures, dp, graphs, shortest paths

Chests and Keys

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

Shifting Dominoes

data structures, geometry, graphs, trees

A Perfect Problem

combinatorics, dp, math

Try Booking

data structures, divide and conquer

Qingshan and Daniel

brute force, data structures, greedy, implementation

Equal LCM Subsets

data structures, math, number theory

New Year and the Tricolore Recreation

games

In a Trap

trees

New Year and Binary Tree Paths

bitmasks, brute force, combinatorics, dp

Reunion

combinatorics, dp, trees

Puzzle Lover

dp, hashing, strings

Yui and Mahjong Set

constructive algorithms, interactive

Wise Men (Hard Version)

bitmasks, dp, math

Invertation in Tournament

brute force, divide and conquer, graphs, math

Election Promises

games, graphs

Pink Floyd

graphs, interactive

Fedya the Potter Strikes Back

data structures, strings

Triple

fft, math

MEX counting

combinatorics, dp, implementation

Mirror Box

matrices, trees

Kyoya and Train

dp, fft, graphs, math, probabilities

New Year and Forgotten Tree

constructive algorithms, flows, graphs

Clockwork Bomb

data structures, dfs and similar, dsu, greedy, trees

Little C Loves 3 III

bitmasks, dp, math

Restoring Map

bitmasks, constructive algorithms, trees

ALT

data structures, flows, graphs, trees

Company Acquisitions

constructive algorithms, math

Weighted Increasing Subsequences

data structures, dp, math

Summer Dichotomy

2-sat, data structures, dfs and similar, greedy

The Maximum Prefix

dp

Digits of Number Pi

dp, implementation, strings

Birthday

graph matchings, strings

The Tree

data structures

Slime and Biscuits

math, probabilities

PolandBall and Many Other Balls

combinatorics, divide and conquer, dp, fft, math, number theory

Choosing Ads

data structures

Security

data structures, string suffix structures

Bear and Bowling

data structures, greedy

Tourists

data structures, dfs and similar, graphs, trees

Equal Trees

*special problem, graphs, meet-in-the-middle

Flower Shop

*special problem, data structures, fft, math

Demonic Invasion

*special problem, flows

Does anyone else hate the wind?

Captain of Knights

math

Road Repair in Treeland

*special problem, binary search, dp, trees

Death Stars (hard)

Arithmancy (Hard)

interactive

Cipher

implementation

Satellites

Polycarpus and Tasks

Division Avoidance

greedy, math

Ber Patio

Parametric Circulation

binary search, flows

Homework

constructive algorithms

Distance Sum

graphs

Unequal Adjacent Elements

constructive algorithms, sortings

Parallel Universes (Hard)

math, matrices

Fugitive Frenzy

math, probabilities

String Theory

geometry, math, strings

Grid Sort

implementation

Intranet of Buses

binary search, geometry, implementation, two pointers

DZY Loves Bridges

math, matrices

Fox and Meteor Shower

geometry

Again Counting Arrays (Easy Version)

combinatorics, dp, fft, math

Freak Joker Process

binary search, data structures, sortings

Duck Hunt

data structures

Show Must Go On

binary search, brute force, greedy, shortest paths

Dreamoon and Notepad

data structures