White Sheet

geometry, math

Radio Stations

2-sat

Marbles

bitmasks, dp

Ticket Game

games, greedy, math

Tiles Placement

constructive algorithms, dfs and similar, trees

Feeling Good

bitmasks, data structures

Employment

greedy, sortings

Petya and Construction Set

constructive algorithms, graphs, math, sortings, trees

Treasure Island

dfs and similar, dp, flows, hashing

Path Queries

divide and conquer, dsu, graphs, sortings, trees

Unstable String Sort

data structures, dfs and similar, dsu, graphs, greedy, implementation, strings

Two Small Strings

brute force, constructive algorithms

Equalizing by Division (hard version)

brute force, math, sortings

Unusual Graph

*special problem, graphs

Road Repair in Treeland

*special problem, binary search, dp, trees

King's Path

*special problem, math, trees

kotlinkotlinkotlinkotlin...

*special problem, graphs, implementation, strings

Double Permutation Inc.

*special problem, binary search, greedy

Teams

*special problem, binary search, greedy, math

Ice Cream

*special problem, greedy, sortings

Mateusz and Escape Room

dp

Marek and Matching (hard version)

brute force, probabilities

Marek and Matching (easy version)

brute force, probabilities

Wojtek and Card Tricks

math

Konrad and Company Evaluation

graphs

Kamil and Making a Stream

math, number theory, trees

Marcin and Training Camp

brute force, greedy

Anadi and Domino

brute force, graphs

Moving Walkways

data structures, greedy, math

Into Blocks (hard version)

data structures

Into Blocks (easy version)

data structures, dsu, greedy, implementation, two pointers

Koala and Notebook

data structures, dfs and similar, graphs, shortest paths, strings, trees

Rotate Columns (hard version)

bitmasks, dp, greedy, sortings

Rotate Columns (easy version)

bitmasks, brute force, dp, greedy, sortings

Cow and Snacks

dfs and similar, dsu, graphs

Red Blue Tree

data structures, implementation, trees

Polygons

greedy, math, number theory

Bits And Pieces

bitmasks, dfs and similar, dp, greedy

Let Them Slide

data structures, implementation

Restore Permutation

binary search, data structures, greedy, implementation

Magic Grid

constructive algorithms

Indie Album

data structures, dfs and similar, hashing, string suffix structures, strings, trees

Remainder Problem

brute force, data structures, implementation

XOR Guessing

bitmasks, interactive, math

Number Of Permutations

combinatorics

Beauty of a Permutation

constructive algorithms, math

Expected Value Again

combinatorics, strings

Almost All

constructive algorithms, trees

Palindromic Paths

implementation, interactive

Shortest Cycle

bitmasks, brute force, graphs, shortest paths

Natasha, Sasha and the Prefix Sums

combinatorics, dp, math, number theory

Kirk and a Binary String (hard version)

data structures, greedy, math, strings

Kirk and a Binary String (easy version)

brute force, greedy, strings

Anna, Svyatoslav and Maps

dp, graphs, greedy, shortest paths

Complete the Projects (hard version)

dp, greedy

Complete the Projects (easy version)

greedy

Remove the Substring (hard version)

binary search, greedy, implementation, two pointers

Remove the Substring (easy version)

greedy, implementation

You Are Given Some Letters...

binary search, implementation, math

You Are Given Some Strings...

brute force, string suffix structures, strings

Print a 1337-string...

combinatorics, constructive algorithms, math, strings

You Are Given a WASD-string...

brute force, data structures, dp, greedy, implementation, math, strings

You Are Given a Decimal String...

brute force, dp, shortest paths

Knightmare (hard)

graphs, interactive, shortest paths

Knightmare (easy)

graphs, interactive, shortest paths

Treasure Hunting

binary search, dp, greedy, implementation

Graph Traveler

brute force, data structures, dfs and similar, dp, graphs, implementation, math, number theory

Compress Words

brute force, hashing, implementation, string suffix structures, strings

White Lines

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

GCD Groups 2

greedy, number theory, probabilities

Rectangle Painting 2

flows, graph matchings, graphs

Rectangle Painting 1

dp

Matching vs Independent Set

constructive algorithms, graphs, greedy, sortings

Welfare State

binary search, brute force, data structures, sortings

MP3

sortings, two pointers

Coloring Game

dp, games, matrices

Culture Code

binary search, combinatorics, data structures, dp, shortest paths, sortings

Yet Another Subarray Problem

dp, greedy, math

K-th Path

brute force, constructive algorithms, shortest paths, sortings

Connected Component on a Chessboard

constructive algorithms, implementation

RGB Substring (hard version)

data structures, dp, implementation, two pointers

Geometers Anonymous Club

data structures, geometry, math, sortings

OpenStreetMap

data structures, two pointers

Submarine in the Rybinsk Sea (hard edition)

combinatorics, math, number theory

Another Meme Problem

dp

Crossword Expert

combinatorics, dp, number theory, probabilities, two pointers

Count The Rectangles

bitmasks, brute force, data structures, geometry, sortings

1-2-K Game

games, math

Tokitsukaze and Powers

number theory, probabilities

Tokitsukaze and Explosion

binary search, greedy

Tokitsukaze and Strange Rectangle

data structures, divide and conquer, sortings, two pointers

Tokitsukaze and Duel

brute force, games, greedy

Tokitsukaze, CSL and Stone Game

games

Problem from Red Panda

combinatorics

Make Equal

dp

Array Beauty

dp

Count Pairs

math, matrices, number theory, two pointers

Add on a Tree: Revolution

constructive algorithms, dfs and similar, implementation, trees

Add on a Tree

trees

Gang Up

flows, graphs