King Kog's Reception

data structures

Ehab and a component choosing problem

dp, greedy, math, trees

The Fair Nut and Rectangles

data structures, dp, geometry

Petya and Graph

flows, graphs

Katya and Segments Sets

data structures, interactive, sortings

Sonya and Matrix Beauty

strings

Privatization of Roads in Berland

flows, graph matchings, graphs

Berkomnadzor

data structures, greedy

Lost Root

interactive, probabilities

Split the Tree

binary search, data structures, dp, greedy, trees

Refactoring

greedy, implementation, strings

Chips Puzzle

constructive algorithms, implementation, math

The Shortest Statement

graphs, shortest paths, trees

Self-exploration

math

Space Isaac

hashing, number theory

Deduction Queries

data structures, dsu

Leaf Sets

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

Maximum Matching

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

Relatively Prime Powers

combinatorics, math, number theory

Covered Points

fft, geometry, number theory

Vasya and Maximum Matching

dp, trees

Restore Array

constructive algorithms

Session in BSU

binary search, dfs and similar, dsu, graph matchings, graphs

The Supersonic Rocket

geometry, hashing, strings

Rest In The Shades

binary search, geometry

Allowed Letters

bitmasks, flows, graph matchings, graphs, greedy

Pave the Parallelepiped

bitmasks, brute force, combinatorics, math, number theory

Median on Segments (General Case Edition)

sortings

Sonya and Ice Cream

binary search, data structures, dp, greedy, shortest paths, trees

One Occurrence

data structures, divide and conquer

GCD Counting

divide and conquer, dp, dsu, number theory, trees

Flow Control

dfs and similar, dp, greedy, trees

Elevator

dp, graphs, shortest paths

Kuro and Topological Parity

dp

Simple Cycles Edges

dfs and similar, graphs, trees

Mahmoud and Ehab and yet another xor task

bitmasks, dp, math, matrices

2 + 2 != 4

Fibonacci String Subsequences

combinatorics, dp, matrices

Cutlet

data structures, dp

Team Work

combinatorics, dp, math

Пограничные врата

Divisibility

constructive algorithms, dp, greedy, number theory

Tanks

dp, greedy, implementation

Jamie and Tree

data structures, trees

Imbalance Value of a Tree

data structures, dsu, graphs, trees

Palindromes in a Tree

bitmasks, data structures, divide and conquer, trees

Logical Expression

bitmasks, dp, shortest paths

Prime Gift

binary search, dfs and similar, math, meet-in-the-middle, number theory, two pointers

Tree Destruction

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

New Year and Rainbow Roads

graphs, greedy, implementation

Party

bitmasks, brute force, dp, graphs

Ratings and Reality Shows

data structures, two pointers

Maximum Element

combinatorics, dp, math

Renovation

constructive algorithms, greedy, sortings

Forbidden Indices

dsu, string suffix structures, strings

The Untended Antiquity

data structures, hashing

Buy Low Sell High

constructive algorithms, data structures, greedy

Gotta Go Fast

binary search, dp

Masha and Cactus

dp, trees

Eleventh Birthday

combinatorics, dp, math

Michael and Charging Stations

binary search, dp, greedy

Berland SU Computer Network

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

Students Initiation

binary search, flows, graphs

Fire in the City

binary search, data structures

Prefix Sums

binary search, brute force, combinatorics, math, matrices

The penguin's game

binary search, constructive algorithms, interactive

String Compression

dp, hashing, string suffix structures, strings

Liar

binary search, dp, hashing, string suffix structures

Karen and Supermarket

brute force, dp, trees

Card Game

binary search, flows, graphs

April Fools' Problem (medium)

binary search, flows, graphs

Send the Fool Further! (hard)

dfs and similar, dp, math, trees

Mike and distribution

constructive algorithms, sortings

Exam Cheating

binary search, dp

Labelling Cities

dfs and similar, graphs, hashing

Till I Collapse

data structures, divide and conquer

Axel and Marston in Bitland

bitmasks, dp, graphs, matrices

Change-free

greedy

Geometrical Progression

brute force, math, number theory

Bacterial Melee

brute force, combinatorics, dp, string suffix structures

PolandBall and White-Red graph

constructive algorithms, graphs, shortest paths

Inversions After Shuffle

data structures, probabilities

Hongcow Buys a Deck of Cards

bitmasks, brute force, dp

Sleep in Class

constructive algorithms, data structures, math, two pointers

Cactusophobia

dfs and similar, flows

Pokermon League challenge

math, probabilities

Underfail

flows

String Set Queries

brute force, data structures, hashing, interactive, string suffix structures, strings

Garlands

data structures

LRU

bitmasks, dp, math, probabilities

Collective Mindsets (hard)

Bear and Square Grid

dfs and similar, dsu, implementation

The Last Fight Between Human and AI

math

Four Divisors

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

Gambling Nim

bitmasks, math, matrices, probabilities

Rotate Matrix

*special problem

Bear and Forgotten Tree 2

dfs and similar, dsu, graphs, trees

Levels and Regions

dp

Little Artem and Random Variable

dp, implementation, math, probabilities

Bear and Contribution

data structures, greedy, sortings, two pointers