A and B

greedy, math

Shuffle Hashing

brute force, implementation, strings

Let's Play the Words?

data structures, hashing, implementation, math

Make Them Odd

greedy, number theory

Happy Birthday, Polycarp!

implementation

Asterisk Substrings

string suffix structures

Four Stones

constructive algorithms

Tree Elimination

dp, trees

Beautiful Rectangle

brute force, combinatorics, constructive algorithms, data structures, greedy, math

Two Fairs

combinatorics, dfs and similar, dsu, graphs

As Simple as One and Two

dp, greedy

Two Bracket Sequences

dp, strings, two pointers

Nearest Opposite Parity

dfs and similar, graphs, shortest paths

Remove One Element

brute force, dp

Yet Another Broken Keyboard

combinatorics, dp, implementation

Snow Walking Robot

constructive algorithms, greedy, implementation

Three Friends

brute force, greedy, math, sortings

Divide The Students

brute force

Common Number

binary search, combinatorics, dp, math

Portals

data structures, dp, greedy, implementation, sortings

Shawarma Tent

brute force, geometry, greedy, implementation

Blocks

greedy, math

Suits

brute force, greedy, math

Xor on Figures

constructive algorithms, fft, math

Number of Components

data structures

Subset with Zero Sum

constructive algorithms, dfs and similar, graphs, math

Awesome Substrings

math, strings

Divide Points

constructive algorithms, geometry, math

Strange Device

constructive algorithms, interactive, math, sortings

Make Good

bitmasks, constructive algorithms, math

Interesting Subarray

constructive algorithms, greedy, math

Card Game

games, greedy, math

Modulo Equality

brute force, sortings

Equation

brute force, math

Happy Cactus

dp

Invertation in Tournament

brute force, divide and conquer, graphs, math

K Integers

binary search, data structures

Domino for Young

dp, greedy, math

Long Beautiful Integer

constructive algorithms, greedy, implementation, strings

Lexicography

constructive algorithms, strings

Key Storage

combinatorics, math

Just Arrange the Icons

greedy, implementation, math

Intriguing Selection

brute force, constructive algorithms, implementation, interactive, sortings

Help BerLine

constructive algorithms

Game Relics

math, probabilities

Foolprüf Security

graphs

Elections

greedy

DevOps Best Practices

constructive algorithms

Cactus Revenge

constructive algorithms

Balls of Buma

Apprentice Learning Trajectory

Red-Blue Graph

dp, graphs, math, matrices, meet-in-the-middle

Permutation Concatenation

string suffix structures

Almost Same Distance

dfs and similar, graphs

Spaceship Solitaire

data structures, greedy, implementation

Decreasing Debts

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

Diverse Matrix

constructive algorithms, greedy, math, number theory

Dice Tower

constructive algorithms, math

Competitive Programmer

chinese remainder theorem, math

Beautiful Mirrors

data structures, dp, math, probabilities

Beautiful Numbers

data structures, implementation, math, two pointers

Beautiful String

constructive algorithms, greedy

Beautiful Fibonacci Problem

constructive algorithms, number theory

Beautiful League

constructive algorithms, flows, graph matchings

Beautiful Bracket Sequence (hard version)

combinatorics, probabilities

Beautiful Bracket Sequence (easy version)

combinatorics, dp, probabilities

Beautiful Mirrors with queries

data structures, probabilities

Beautiful Sequence

brute force, constructive algorithms, greedy

Beautiful Regional Contest

greedy, implementation

Economic Difficulties

data structures, dfs and similar, dp, flows, graphs, trees

Editor

data structures, implementation

Secret Passwords

dfs and similar, dsu, graphs

Everyone is a Winner!

binary search, math, meet-in-the-middle, number theory

PIN Codes

greedy, implementation

Sweet Problem

math

Xor-Set

bitmasks, divide and conquer, math

Colored Tree

data structures, trees

Tournament

brute force, dp, greedy

A Game with Traps

binary search, dp, greedy, sortings

Infinite Fence

greedy, math, number theory

Obtain Two Zeroes

binary search, math

Heating

math

Divisor Set

divide and conquer, fft, greedy, math, number theory

Make Them Similar

bitmasks, brute force, hashing, meet-in-the-middle

The Contest

data structures, dp, greedy

Yet Another Monster Killing Problem

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

Dominated Subarray

greedy, implementation, sortings, strings, two pointers

Magic Stick

math

Two Rival Students

greedy, math

Equalizing Two Strings

constructive algorithms, sortings, strings

Yet Another Division Into Teams

dp, greedy, sortings

Binary String Minimizing

greedy

Platforms Jumping

greedy

Minimize the Permutation

greedy

Payment Without Change

math

League of Leesins

constructive algorithms, implementation

Fridge Lockers

graphs, implementation

Changing Volume

math

Send Tree to Charlie

combinatorics, dfs and similar, dsu, trees

Tree Queries

data structures, probabilities, trees