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

Emotional Fishermen

combinatorics, dp, math, two pointers

Make It Increasing

binary search, constructive algorithms, data structures, dp, implementation

Minimal Height Tree

graphs, greedy, shortest paths, trees

Chef Monocarp

dp, flows, graph matchings, greedy, math, sortings

Sum Over Subsets

combinatorics, math, number theory

Complicated Computations

binary search, data structures, two pointers

Bandit in a City

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

Binary Search

binary search, combinatorics

A Convex Game

dsu, games

Reducing Delivery Cost

brute force, graphs, shortest paths

Zero Remainder Sum

dp

Zero-XOR Array

*special problem, dp

Cyclic Shifts

*special problem, strings

Rogue-like Game

*special problem, brute force, greedy, two pointers

Number Deletion Game

*special problem, dp, games, greedy

Neural Network Problem

*special problem, binary search, greedy

Chess Match

*special problem

Used Markers

*special problem, greedy

Black Friday

*special problem, implementation

Polycarp and the Language of Gods

*special problem, implementation, two pointers

Yet Another DAG Problem

bitmasks, dfs and similar, dp, flows, graphs, math

Realistic Gameplay

dp, greedy

String Reversal

data structures, greedy, strings