Hanging Hearts

constructive algorithms, data structures, dfs and similar, dp, greedy, trees

Pair Of Lines

geometry

R2D2 and Droid Army

binary search, data structures, two pointers

Balanced Removals (Harder)

binary search, constructive algorithms, divide and conquer, greedy, implementation, sortings

Kostya the Sculptor

data structures, hashing

Fire

dp, sortings

Reducing Delivery Cost

brute force, graphs, shortest paths

Save the problem!

constructive algorithms

Robbers' watch

brute force, combinatorics, dp, math

Polyline

constructive algorithms, implementation

Palindrome Pairs

hashing, strings

Sequence

dp, sortings

Energy exchange

binary search

Lucky Tickets

greedy

Pairs of Segments

data structures, greedy, sortings, two pointers

Perfect Security

data structures, greedy, strings, trees

Curriculum Vitae

brute force, implementation

Equalize the Remainders

data structures, greedy, implementation

Imbalanced Arrays

constructive algorithms, graphs, greedy, math, sortings, two pointers

Searchlights

binary search, brute force, data structures, dp, implementation, sortings, two pointers

Constellation

geometry, implementation

Organizing SWERC

brute force, implementation

Trash Problem

data structures, implementation

Taxi drivers and Lyft

implementation, sortings

Wish I Knew How to Sort

dp, math, probabilities

XOR Inverse

bitmasks, data structures, divide and conquer, dp, greedy, math, sortings, strings, trees

View Angle

brute force, geometry, math

Equal XOR Segments

binary search, data structures

New Year Snowmen

binary search, data structures, greedy

Are You a Procrastinator?

implementation

Archaeology

brute force, constructive algorithms, greedy, strings

Different Arrays

brute force, dp, implementation

Nearest Beautiful Number (hard version)

bitmasks, brute force, constructive algorithms, dfs and similar, dp, greedy

Petya's Exams

greedy, implementation, sortings

Bitwise Queries (Easy Version)

bitmasks, constructive algorithms, interactive, math

Sasha and a Walk in the City

combinatorics, dp, math, trees

Another Sorting Problem

data structures, sortings, strings

Depression

geometry, math

Candies Distribution

constructive algorithms, implementation

Divide by Three

dp, greedy, math, number theory

Optimal Subsequences (Hard Version)

data structures, greedy

Lorry

greedy, sortings

Robot Vacuum Cleaner

greedy, sortings

Orac and Game of Life

dfs and similar, graphs, implementation, shortest paths

Finding Zero

constructive algorithms, interactive, math

Lucky Mask

brute force, implementation

Chloe and pleasant prizes

dfs and similar, dp, graphs, trees

Pairs

binary search, constructive algorithms, greedy, two pointers

Palindrome pairs

*special problem, brute force, dp, strings

Line

math, number theory

Restore the Permutation

binary search, constructive algorithms, data structures, greedy, math

Madoka and The Corruption Scheme

combinatorics, constructive algorithms, greedy, math

Danil and a Part-time Job

bitmasks, data structures, trees

Sasha and One More Name

constructive algorithms, hashing, strings

Subsequences of Length Two

dp, strings

Timetable

dp

Guess Your Way Out!

implementation, math, trees

Mind the Gap

implementation

Colliders

math, number theory

Nastia and a Hidden Permutation

constructive algorithms, interactive

Sereja and Algorithm

data structures, implementation

Weakness and Poorness

ternary search

Iterated Linear Function

math, number theory

Guess The String

binary search, constructive algorithms, interactive

Binary Median

binary search, bitmasks, brute force, constructive algorithms

Marco and GCD Sequence

constructive algorithms, math

Empty Graph

binary search, constructive algorithms, data structures, greedy, shortest paths

Block Towers

brute force, greedy, math, number theory

Inconvenient Pairs

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

Tolik and His Uncle

constructive algorithms

Messages

math

Send the Fool Further! (easy)

dfs and similar, graphs, trees

Swaps Again

constructive algorithms, implementation, sortings

Poster

greedy, implementation

Identify the Operations

combinatorics, data structures, dsu, greedy, implementation

Save Energy!

binary search, implementation, math

Two Paths

dfs and similar, dp, graphs, shortest paths, trees, two pointers

Blocking Elements

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

Mahmoud and a Message

brute force, dp, greedy, strings

Efim and Strange Grade

dp, implementation, math

Dreamoon and Sets

constructive algorithms, greedy, math

Petya and Exam

implementation, strings

Spongebob and Joke

implementation

Robot Collisions

data structures, greedy, implementation, sortings

Trivial Conjecture

*special problem, constructive algorithms, math, number theory

Igor and his way to work

dfs and similar, graphs, implementation, shortest paths

Masha and geometric depression

brute force, implementation, math

Jumping Jack

math

Passable Paths (hard version)

data structures, dfs and similar, trees

Treasure Hunt

greedy

LuoTianyi and the Floating Islands (Easy Version)

combinatorics, math, probabilities, trees

Vanya and Triangles

brute force, combinatorics, data structures, geometry, math, sortings

Count Pairs

math, matrices, number theory, two pointers

The Strongest Build

binary search, brute force, data structures, dfs and similar, graphs, greedy, hashing, implementation

Mysterious numbers - 1

*special problem, constructive algorithms

Thematic Contests

greedy, sortings

Directed Roads

combinatorics, dfs and similar, graphs, math

Graph and String

constructive algorithms, graphs

Multi-judge Solving

greedy, implementation

The Intriguing Obsession

combinatorics, dp, math