Road Reform

dsu, graphs, greedy

Plane Tiling

geometry, implementation, math

K and Medians

constructive algorithms, greedy, math

Hobbits

binary search, geometry

Full Turn

geometry, hashing, number theory

Firecrackers

binary search, sortings

Berpizza

data structures, implementation

Bakery

data structures, dsu

LaIS

data structures, dp, greedy

Distinctive Roots in a Tree

data structures, dfs and similar, dp, trees

Sum of Paths

combinatorics, dp, math

Three Bags

constructive algorithms, greedy

Hills And Valleys

brute force, implementation

The Riddle of the Sphinx

binary search, data structures, data structures, interactive

Finding satisfactory solutions

combinatorics, dp, graphs, greedy, math

Song of the Sirens

combinatorics, divide and conquer, hashing, math, string suffix structures, strings

Euclid's nightmare

bitmasks, dfs and similar, dsu, graphs, greedy, math, sortings

Apollo versus Pan

bitmasks, brute force, math

13th Labour of Heracles

data structures, greedy, sortings, trees

My Beautiful Madness

data structures, trees

Max Correct Set

bitmasks, dp, math

Plan of Lectures

constructive algorithms, dfs and similar, dsu, graphs, implementation, sortings, trees

Pairs

binary search, constructive algorithms, greedy, two pointers

Busy Robot

implementation

Find The Array

bitmasks, constructive algorithms, greedy

The Treasure of The Segments

binary search, data structures, greedy

Close Tuples (hard version)

binary search, combinatorics, implementation, math, sortings, two pointers

Close Tuples (easy version)

binary search, combinatorics, math, sortings, two pointers

Add to Neighbour and Remove

greedy, math, number theory

Mathematical Expression

constructive algorithms, dp, greedy

Water Level

brute force, graphs, greedy, implementation, math

Divide and Summarize

binary search, brute force, data structures, divide and conquer, implementation, sortings

Random Events

dp, math, probabilities

Find the Spruce

brute force, dp, implementation

Range Diameter Sum

data structures, trees

Nim Shortcuts

data structures, games

Flip and Reverse

data structures, graphs, greedy

Latin Square

math, matrices

Glass Half Spilled

dp

Row GCD

math, number theory

XOR-ranges

dp, greedy

Forbidden Value

data structures, dp

String and Operations

dp, greedy

Four Points

brute force, constructive algorithms, flows, geometry, greedy, implementation, math, ternary search

Sequence and Swaps

dp, greedy, sortings

Array Partition

binary search, data structures, greedy, two pointers

Number of Simple Paths

combinatorics, dfs and similar, graphs, trees

Even Harder

dp

Dog Snacks

binary search, dfs and similar, dp, greedy, trees

Checkpoints

brute force, constructive algorithms, greedy, math, probabilities

Triangles

greedy, implementation

Suffix Operations

constructive algorithms, implementation

Game On Tree

data structures, dfs and similar, greedy, trees

Divide Powers

constructive algorithms, greedy

Two Editorials

brute force, dp, greedy, sortings, two pointers

Radio Towers

combinatorics, dp, math

Toy Blocks

binary search, greedy, math, sortings

Nullify The Matrix

constructive algorithms, games

Bitwise Queries (Hard Version)

bitmasks, constructive algorithms, interactive, math

Bitwise Queries (Easy Version)

bitmasks, constructive algorithms, interactive, math

Circle Game

games, geometry, math

String Equality

dp, greedy, hashing, implementation, strings

Multithreading (Hard Version)

combinatorics, implementation, math

Multithreading (Easy Version)

combinatorics, fft, math

Communism

bitmasks, dp, trees

The Struggling Contestant

constructive algorithms, greedy

Capitalism

constructive algorithms, dfs and similar, graphs, shortest paths

Rating Compression

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

Errich-Tac-Toe (Hard Version)

constructive algorithms, math

Errich-Tac-Toe (Easy Version)

constructive algorithms, math

Line Distance

binary search, data structures, geometry

Long Recovery

constructive algorithms, dfs and similar

Frequency Problem (Hard Version)

data structures, greedy, two pointers

Frequency Problem (Easy Version)

data structures, greedy

Xor Tree

binary search, bitmasks, data structures, divide and conquer, dp, trees

Catching Cheaters

dp, strings

Finding the Vertex

brute force, dfs and similar, dp, interactive, trees

Rectangular Polyline

constructive algorithms, dp, geometry

Team-Building

data structures, dfs and similar, dsu, graphs

Divide and Sum

combinatorics, math, sortings

Division

brute force, math, number theory

Long Permutation

brute force, math, two pointers

The Delivery Dilemma

binary search, greedy, sortings

Differentiating Games

games, interactive

Black, White and Grey Tree

binary search, constructive algorithms, dfs and similar, dp, greedy, trees

Sum

data structures, divide and conquer, dp, greedy

Graph Transpositions

dfs and similar, graphs, greedy, shortest paths

Identify the Operations

combinatorics, data structures, dsu, greedy, implementation

Extreme Subtraction

constructive algorithms, dp, greedy

Cheat and Win

bitmasks, data structures, games, trees

INOI Final Contests

combinatorics, dp, fft

Greedy Shopping

binary search, data structures, divide and conquer, greedy, implementation

Graph Subset Problem

constructive algorithms, data structures, graphs

Binary Table (Hard Version)

constructive algorithms, graphs, greedy, implementation

Binary Table (Easy Version)

constructive algorithms, implementation

Olha and Igor

interactive, probabilities, trees

Yurii Can Do Everything

binary search, bitmasks, brute force, constructive algorithms, divide and conquer, two pointers

Powerful Ksenia

bitmasks, constructive algorithms, math

Engineer Artem

2-sat, chinese remainder theorem, constructive algorithms, fft, flows

Death DBMS

data structures, string suffix structures, strings, trees