Sum over all Substrings (Hard Version)

bitmasks, divide and conquer, dp, dsu, greedy, implementation, strings

Counting Binary Strings

combinatorics, dp, math

Neko and Aki's Prank

dp, greedy, trees

Two strings

binary search, hashing, strings, two pointers

Rain

binary search, brute force, data structures, geometry, greedy, implementation, math

Red-Black Number

dfs and similar, dp, implementation, math, meet-in-the-middle

Counting Shortcuts

data structures, dfs and similar, dp, graphs, shortest paths

Carry Bit

combinatorics, math

Wi-Fi

data structures, dp, greedy

Unstable String Sort

data structures, dfs and similar, dsu, graphs, greedy, implementation, strings

Lunar New Year and Red Envelopes

data structures, dp

Underground Lab

constructive algorithms, dfs and similar, graphs

Space Harbour

data structures, implementation, math, sortings

Treasure Hunting

binary search, dp, greedy, implementation

Weird journey

combinatorics, constructive algorithms, dfs and similar, dsu, graphs

Hot Start Up (hard version)

data structures, dp

Candy Party (Hard Version)

bitmasks, constructive algorithms, dp, greedy, implementation, math

Subway Pursuit

binary search, interactive, probabilities

Analysis of Pathes in Functional Graph

data structures, graphs

Sand Fortress

binary search, constructive algorithms, math

Rearrange Brackets

brute force, dp, greedy, sortings, strings

Leha and another game about graph

constructive algorithms, data structures, dfs and similar, dp, graphs

Staircases

brute force, combinatorics, data structures, dfs and similar, dp, implementation, math

Turtle Mission: Robot and the Earthquake

dfs and similar, dp, graphs, shortest paths

Rain and Umbrellas

dp

Cartons of milk

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

Well played!

greedy, sortings

The Harmonization of XOR

bitmasks, constructive algorithms, greedy, math

Ball Sorting

data structures, dp, sortings

Mashmokh and Reverse Operation

combinatorics, divide and conquer

Petya, Petya, Petr, and Palindromes

binary search, brute force, data structures, two pointers

Polygons

geometry, sortings

Ralph and Mushrooms

dp, graphs

Autosynthesis

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

Fedor and coupons

binary search, data structures, greedy, sortings

Array and Segments (Hard version)

data structures, implementation

Yaroslav and Time

binary search, graphs, shortest paths

The Queue

brute force, greedy

Towers

dp, greedy, two pointers

Random Task

binary search, bitmasks, combinatorics, dp, math

The Holmes Children

math, number theory

Spaceship Solitaire

data structures, greedy, implementation

Cut Substrings

combinatorics, dp, hashing, strings, two pointers

Information Graph

dfs and similar, dsu, graphs, trees

The way home

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

Apple Tree

dfs and similar, number theory, trees

Maximal Area Quadrilateral

brute force, geometry

Permutation Sorting

data structures, sortings

Lengthening Sticks

combinatorics, implementation, math

Infinite Inversions

binary search, data structures, implementation, sortings, trees

Lipshitz Sequence

data structures, math

Messenger

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

Time to Raid Cowavans

brute force, data structures, sortings

Check Transcription

brute force, data structures, hashing, strings

Arpa and a list of numbers

implementation, number theory

Post Lamps

brute force, greedy

Field expansion

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

Assimilation IV

combinatorics, dp, math, probabilities, two pointers

Down or Right

constructive algorithms, interactive, matrices

Fishes

data structures, graphs, greedy, probabilities, shortest paths

Another Wine Tasting Event

combinatorics, constructive algorithms, math, strings

National Property

2-sat, dfs and similar, graphs, implementation

Vlad and the Nice Paths (easy version)

combinatorics, dp, math

Solo mid Oracle

greedy, math, ternary search

Lucky Subsequence

combinatorics, dp, math

Compress String

dp, strings

Inverse Coloring

combinatorics, dp, math

Characteristics of Rectangles

binary search, bitmasks, brute force, implementation, sortings

Transitive Graph

dfs and similar, dp, dsu, graphs, implementation

Congruence Equation

chinese remainder theorem, math, number theory

Santa Claus and a Palindrome

constructive algorithms, data structures, greedy

Dispute

dfs and similar, graphs, greedy

Two Pizzas

bitmasks, brute force

Digits

dp, math, number theory

Addition Robot

data structures, math, matrices

Degenerate Matrix

binary search, math

Topforces Strikes Back

brute force, math, sortings

Yet another 2D Walking

dp

Broken BST

data structures, dfs and similar

Destroy it!

dp, implementation, sortings

Key Storage

combinatorics, math

Is It Flower?

dfs and similar, graphs, implementation

GukiZ and Binary Operations

combinatorics, implementation, math, matrices, number theory

Colorful Points

data structures, greedy, implementation

Order book

combinatorics, data structures, greedy

Chip 'n Dale Rescue Rangers

binary search, geometry, math

Permutation recovery

constructive algorithms, data structures, dfs and similar, graphs, greedy, math, sortings

Full Binary Tree Queries

brute force, implementation, trees

Light Bulbs (Easy Version)

brute force, combinatorics, dfs and similar, dp, dsu, graphs, math, trees

Greg and Friends

combinatorics, dp, graphs, shortest paths

Substitutes in Number

dp

Desk Disorder

combinatorics, dfs and similar, dsu, graphs, trees

Distributing Parts

greedy, sortings

Flawed Flow

constructive algorithms, flows, graphs, greedy

Berland and the Shortest Paths

brute force, dfs and similar, graphs, shortest paths

DNA Evolution

data structures, strings

Nastya and a Game

brute force, implementation, math

Special Matrices

combinatorics, dp

Chris and Road

geometry, implementation

Beard Graph

data structures, dsu, trees