Broken BST

data structures, dfs and similar

Little Elephant and LCM

binary search, combinatorics, dp, math

Sereja and Subsequences

data structures, dp

Yet another 2D Walking

dp

Pretty Song

math, strings

Microtransactions (easy version)

binary search, greedy

Topforces Strikes Back

brute force, math, sortings

Degenerate Matrix

binary search, math

Addition Robot

data structures, math, matrices

Digits

dp, math, number theory

Two Pizzas

bitmasks, brute force

Beaver Game

dp, games, number theory

Mike and Geometry Problem

combinatorics, data structures, dp, geometry, implementation

Dispute

dfs and similar, graphs, greedy

Geo Game

greedy, interactive, math

Santa Claus and a Palindrome

constructive algorithms, data structures, greedy

Giving Awards

dfs and similar

Theseus and labyrinth

graphs, implementation, shortest paths

Congruence Equation

chinese remainder theorem, math, number theory

Water Taps

binary search, greedy, sortings

Transitive Graph

dfs and similar, dp, dsu, graphs, implementation

The Fair Nut and Strings

greedy, strings

Characteristics of Rectangles

binary search, bitmasks, brute force, implementation, sortings

Inverse Coloring

combinatorics, dp, math

Ghosts

geometry, math

A Determined Cleanup

math

Twisted Circuit

*special problem, brute force, implementation

Lucky Subsequence

combinatorics, dp, math

Compress String

dp, strings

The hat

binary search, interactive

Castle Defense

binary search, data structures, greedy, two pointers

Dasha and Puzzle

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

Solo mid Oracle

greedy, math, ternary search

Elongated Matrix

binary search, bitmasks, brute force, dp, graphs

Vlad and the Nice Paths (easy version)

combinatorics, dp, math

National Property

2-sat, dfs and similar, graphs, implementation

Two out of Three

dp

Olympiad in Programming and Sports

dp, flows, graphs, greedy

Dima and Containers

constructive algorithms, greedy, implementation

Another Wine Tasting Event

combinatorics, constructive algorithms, math, strings

Down or Right

constructive algorithms, interactive, matrices

Fishes

data structures, graphs, greedy, probabilities, shortest paths

Assimilation IV

combinatorics, dp, math, probabilities, two pointers

Field expansion

brute force, dp, meet-in-the-middle

Post Lamps

brute force, greedy

Arpa and a list of numbers

implementation, number theory

Helga Hufflepuff's Cup

dp, trees

Check Transcription

brute force, data structures, hashing, strings

Time to Raid Cowavans

brute force, data structures, sortings

Messenger

data structures, hashing, implementation, string suffix structures, strings

Cloud Computing

data structures, greedy

Lipshitz Sequence

data structures, math

Sums of Digits

dp, greedy, implementation

Lengthening Sticks

combinatorics, implementation, math

Infinite Inversions

binary search, data structures, implementation, sortings, trees

Let's Play the Hat?

brute force, constructive algorithms, greedy, math

Stripe 2

binary search, dp, sortings

Permutation Sorting

data structures, sortings

Maximal Area Quadrilateral

brute force, geometry

Microtransactions (hard version)

binary search, greedy, implementation

Apple Tree

dfs and similar, number theory, trees

PLEASE

combinatorics, dp, implementation, math, matrices

Ithea Plays With Chtholly

binary search, constructive algorithms, games, greedy, interactive

The way home

binary search, data structures, dp, graphs, greedy, shortest paths, sortings

Information Graph

dfs and similar, dsu, graphs, trees

Cut Substrings

combinatorics, dp, hashing, strings, two pointers

Greedy Arkady

math

Spaceship Solitaire

data structures, greedy, implementation

World Tour

graphs, shortest paths

Yaroslav and Two Strings

combinatorics, dp

The Holmes Children

math, number theory

Roma and Poker

dp, graphs

Random Task

binary search, bitmasks, combinatorics, dp, math

Towers

dp, greedy, two pointers

The Queue

brute force, greedy

Yaroslav and Time

binary search, graphs, shortest paths

An overnight dance in discotheque

dfs and similar, dp, geometry, greedy, trees

Infinite Maze

dfs and similar, graphs

Array and Segments (Hard version)

data structures, implementation

Fedor and coupons

binary search, data structures, greedy, sortings

Vitaly and Cycle

combinatorics, dfs and similar, graphs, math

Area of Two Circles' Intersection

geometry

Autosynthesis

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

Interactive LowerBound

brute force, interactive, probabilities

Ralph and Mushrooms

dp, graphs

Wrong Answer

constructive algorithms

Polygons

geometry, sortings

Industrial Nim

games

Petya, Petya, Petr, and Palindromes

binary search, brute force, data structures, two pointers

Anya and the Mysterious String

binary search, data structures

Mashmokh and Reverse Operation

combinatorics, divide and conquer

Ball Sorting

data structures, dp, sortings

The Harmonization of XOR

bitmasks, constructive algorithms, greedy, math

Well played!

greedy, sortings

Cartons of milk

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

Rain and Umbrellas

dp

Turtle Mission: Robot and the Earthquake

dfs and similar, dp, graphs, shortest paths

Tokitsukaze and Strange Rectangle

data structures, divide and conquer, sortings, two pointers

Multi-Colored Segments

binary search, data structures, math, sortings

Copy of a Copy of a Copy

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