Hot is Cold

bitmasks, data structures, divide and conquer, implementation

Parquet

combinatorics, constructive algorithms, greedy, implementation

Small Permutation Problem (Hard Version)

combinatorics, dp, math

Ladies' Shop

constructive algorithms, fft, math

Balancing Weapons

binary search, brute force, data structures, math, two pointers

Code Review

*special problem

Indecisive Taxi Fee

data structures, graphs, shortest paths

Frog Jumping

*special problem, math

Generate superposition of all basis states

April Fools' Problem (hard)

binary search, data structures, flows

Numbers

dp, math, number theory

Max Sum Array

combinatorics, constructive algorithms, greedy, sortings

GCD Groups 2

greedy, number theory, probabilities

Monsters and Potions

brute force, dp, greedy, implementation

Buying Sets

flows, graph matchings

The Tree Has Fallen!

bitmasks, dfs and similar, math, trees

Comfortably Numb

bitmasks, data structures, divide and conquer, strings, trees

Apprentice Learning Trajectory

Balance

dp

Colorful Constructive

constructive algorithms, data structures, greedy

Curfew

binary search, brute force, greedy, sortings

Baby Ehab Plays with Permutations

combinatorics, dp, math

Contact ATC

Gotta Go Fast

binary search, dp

Casinos and travel

dp

E-mail Addresses

implementation

Divan and a Cottage

binary search, data structures

The Supersonic Rocket

geometry, hashing, strings

Airplane Arrangements

math, number theory

PolandBall and White-Red graph

constructive algorithms, graphs, shortest paths

Survival of the Weakest (easy version)

binary search, brute force, implementation, math, sortings

Guess Divisors Count

constructive algorithms, interactive, number theory

Playing on Graph

graphs, shortest paths

Brand New Easy Problem

brute force

Slime and Biscuits

math, probabilities

Wise Men (Easy Version)

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

Closing ceremony

greedy

Table with Letters - 2

brute force, two pointers

Thwarting Demonstrations

binary search, data structures, trees

Clearing Up

constructive algorithms, dp, dsu, graphs

Fibonacci Sums

dp, math

Lexichromatography

combinatorics, dfs and similar, dsu, graphs, two pointers

Boboniu and Jianghu

dp, greedy, sortings, trees

Tree Queries

data structures, dfs and similar, graphs, implementation, trees

Split

binary search, data structures, divide and conquer, dsu, math, trees, two pointers

Abnormal Permutation Pairs (hard version)

combinatorics, dp, fft, math

Danger of Mad Snakes

combinatorics, dp, math

Superset

constructive algorithms, divide and conquer

Elevator

dp, graphs, shortest paths

Even Harder

dp

Complete Mirror

constructive algorithms, dfs and similar, dp, hashing, implementation, trees

Autocompletion

*special problem, strings, trees

Off by One

constructive algorithms, dfs and similar, geometry, graphs, sortings, trees

Greedy Change

constructive algorithms

Hobbits

binary search, geometry

Nested Rubber Bands

constructive algorithms, dfs and similar, dp, math, trees

Red-White Fence

combinatorics, fft

Research Rover

combinatorics, dp

General Mobilization

data structures, dfs and similar, sortings

Nastya and Time Machine

constructive algorithms, dfs and similar, graphs, trees

A Museum Robbery

data structures, dp

Tavas and Pashmaks

geometry, math

The Coronation

graphs, implementation

String Journey

data structures, dp, string suffix structures

Singer House

combinatorics, dp, graphs, trees

Dark Assembly

brute force, probabilities

Letter A

geometry, implementation

The Neutral Zone

brute force, math

Preorder Test

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

Bear and Floodlight

bitmasks, dp, geometry

Petya and Pipes

flows, graphs, shortest paths

Robo-Footballer

binary search, geometry

Village (Maximum)

*special problem, dfs and similar, trees

Zoning Restrictions

dp, flows, graphs

Putting Boxes Together

data structures

Two Tanks

binary search, dp, implementation, math

Mystery Circuit

bitmasks, brute force

The Tree

data structures

Pentagonal numbers

*special problem, implementation

Rusty String

fft, math, strings

Freezing with Style

binary search, data structures, divide and conquer, trees

Serious Business

data structures, divide and conquer, dp, implementation, shortest paths

The Check of the Point

*special problem, geometry

Board Game

data structures, dfs and similar

Traveling Graph

bitmasks, graph matchings, graphs

New Year and the Mallard Expedition

constructive algorithms, greedy

XOR, Tree, and Queries

bitmasks, constructive algorithms, dfs and similar, dsu, graphs, greedy, implementation, trees

Playoff Restoration

bitmasks, brute force, hashing, implementation, meet-in-the-middle

Alphabet Permutations

data structures, strings

Wonderful Jump

dp, greedy

Set of Points

constructive algorithms, geometry

Bear and Contribution

data structures, greedy, sortings, two pointers

Keep XOR Low

bitmasks, combinatorics, data structures, divide and conquer, dp, math

Johnny Solving

constructive algorithms, dfs and similar, graphs, math

Marbles

hashing, strings

LCS Again

dp, greedy

Kamal-ol-molk's Painting

brute force, constructive algorithms, greedy

Unsolvable

math, number theory

Tick, Tock

combinatorics, dfs and similar, dsu, graphs

Captain America

flows, greedy