Number Busters

binary search, math

Digital Root

number theory

Police Patrol

greedy, implementation, math, ternary search

MYSTERIOUS LANGUAGE

*special problem

Rectangle Puzzle

geometry

Sereja and Periods

binary search, dfs and similar, strings

New Year Letter

bitmasks, brute force, dp

Olya and magical square

constructive algorithms, implementation, math

Restoring Increasing Sequence

binary search, brute force, greedy, implementation

Second price auction

bitmasks, probabilities

Circular Mirror

binary search, combinatorics, geometry, math, two pointers

Wires

dfs and similar, graphs, greedy

Ants

brute force, implementation

Bubble Strike

combinatorics, math, probabilities, ternary search

Build String

flows, graphs

Vanya and Field

math

Minimal Diameter Forest

constructive algorithms, dfs and similar, greedy, trees

International Olympiad

constructive algorithms, greedy, implementation, math

Mahmoud and Ehab and the binary string

binary search, divide and conquer, interactive

Restore Cube

brute force, geometry

Jamie and Binary Sequence (changed after round)

bitmasks, greedy, math

Sereja and the Arrangement of Numbers

graphs, greedy, sortings

Gifts by the List

constructive algorithms, dfs and similar, graphs, trees

Big Maximum Sum

data structures, dp, greedy, implementation, math, trees

Restoration of string

constructive algorithms, graphs, implementation

Polycarp and Hay

dfs and similar, dsu, graphs, greedy, sortings

Little Elephant and LCM

binary search, combinatorics, dp, math

Sereja and Subsequences

data structures, dp

Microtransactions (easy version)

binary search, greedy

Pretty Song

math, strings

Geo Game

greedy, interactive, math

Giving Awards

dfs and similar

Water Taps

binary search, greedy, sortings

Beaver Game

dp, games, number theory

Mike and Geometry Problem

combinatorics, data structures, dp, geometry, implementation

Theseus and labyrinth

graphs, implementation, shortest paths

The Fair Nut and Strings

greedy, strings

Ghosts

geometry, math

Twisted Circuit

*special problem, brute force, implementation

A Determined Cleanup

math

Dasha and Puzzle

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

The hat

binary search, interactive

Castle Defense

binary search, data structures, greedy, two pointers

Elongated Matrix

binary search, bitmasks, brute force, dp, graphs

Two out of Three

dp

Olympiad in Programming and Sports

dp, flows, graphs, greedy

Dima and Containers

constructive algorithms, greedy, implementation

Helga Hufflepuff's Cup

dp, trees

Sums of Digits

dp, greedy, implementation

Cloud Computing

data structures, greedy

Let's Play the Hat?

brute force, constructive algorithms, greedy, math

Stripe 2

binary search, dp, sortings

Microtransactions (hard version)

binary search, greedy, implementation

PLEASE

combinatorics, dp, implementation, math, matrices

Ithea Plays With Chtholly

binary search, constructive algorithms, games, greedy, interactive

Yaroslav and Two Strings

combinatorics, dp

Greedy Arkady

math

World Tour

graphs, shortest paths

Roma and Poker

dp, graphs

Infinite Maze

dfs and similar, graphs

An overnight dance in discotheque

dfs and similar, dp, geometry, greedy, trees

Vitaly and Cycle

combinatorics, dfs and similar, graphs, math

Interactive LowerBound

brute force, interactive, probabilities

Area of Two Circles' Intersection

geometry

Anya and the Mysterious String

binary search, data structures

Wrong Answer

constructive algorithms

Industrial Nim

games

Multi-Colored Segments

binary search, data structures, math, sortings

Tokitsukaze and Strange Rectangle

data structures, divide and conquer, sortings, two pointers

Copy of a Copy of a Copy

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

Om Nom and Candies

brute force, greedy, math

Maxim and Array

constructive algorithms, data structures, greedy, math

Running Track

dp, greedy, strings, trees

Unusual Minesweeper

binary search, dfs and similar, dsu, greedy, sortings

Candy Box (hard version)

greedy, implementation, sortings

Cipher

combinatorics, dp

The World Is Just a Programming Task (Easy Version)

brute force, dp, greedy, implementation

Ant on the Tree

constructive algorithms, dfs and similar, trees

TV Shows

data structures, greedy, implementation, sortings

Work Group

dfs and similar, dp, graphs, strings, trees

Iahub and Permutations

combinatorics, math

Divisors

interactive, math, number theory

Berzerk

dfs and similar, dp, games

Misha and Permutations Summation

data structures

Mars rover

dfs and similar, graphs, implementation, trees

Pinball

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

Remove Directed Edges

dfs and similar, dp, graphs

Messages

brute force, dp, greedy, probabilities, sortings

One-Dimensional Puzzle

combinatorics, math, number theory

Freedom of Choice

brute force, greedy, implementation

Polycarp and Snakes

brute force, implementation

Stack Sorting

constructive algorithms, data structures, greedy, implementation

PolandBall and Polygon

data structures

Jeremy Bearimy

dfs and similar, graphs, greedy, trees

Multicolored Markers

binary search, brute force, math, number theory

Leaving Auction

binary search, data structures

Maximum Balanced Circle

constructive algorithms, dp, greedy, two pointers

Petya and Construction Set

constructive algorithms, graphs, math, sortings, trees

Cards and Joy

dp

New Year and Ancient Prophecy

dp, hashing, strings