Coprime Permutation

combinatorics, number theory

Cron

Limak and Shooting Points

brute force, geometry, math

LRU

bitmasks, dp, math, probabilities

Fix a Tree

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

...Dary!

binary search, geometry, two pointers

...Wait for it...

data structures, dsu, trees

Legen...

data structures, dp, matrices, strings

PLEASE

combinatorics, dp, implementation, math, matrices

Puzzles

dfs and similar, math, probabilities, trees

Couple Cover

brute force, dp, number theory

Xor-sequences

matrices

Swaps in Permutation

dfs and similar, dsu, math

Exponential notation

implementation, strings

s-palindrome

implementation, strings

Tree of Life (hard)

trees

Tree of Life (medium)

constructive algorithms, hashing, trees

Photographs (II)

Photographs (I)

The Wall (hard)

dp

The Wall (medium)

combinatorics

Brain Network (hard)

trees

Recover Polygon (hard)

data structures

Recover Polygon (medium)

geometry

Recover Polygon (easy)

Collective Mindsets (hard)

Collective Mindsets (medium)

Mike and Geometry Problem

combinatorics, data structures, dp, geometry, implementation

Friends and Subsequences

binary search, data structures

Mike and Chocolate Thieves

binary search, combinatorics, math

Mike and Shortcuts

dfs and similar, graphs, greedy, shortest paths

TOF

dfs and similar, graphs

Dividing Kingdom II

brute force, data structures, dsu, graphs, sortings

The Values You Can Make

dp

Remainders Game

chinese remainder theorem, math, number theory

Travelling Through the Snow Queen's Kingdom

bitmasks, brute force, divide and conquer, graphs

Kay and Eternity

brute force, implementation, sortings

Optimal Point

binary search, math

Kay and Snowflake

data structures, dfs and similar, dp, trees

Robbers' watch

brute force, combinatorics, dp, math

The Hero with Bombs

*special problem

Loader

*special problem, graphs

Exchange of Books

*special problem

The Fraction

*special problem

Reformat the String

*special problem

Hammer throwing

*special problem

Symmetric Difference

*special problem

The Teacher of Physical Education

*special problem

Alyona and Triangles

geometry, two pointers

Alyona and Strings

dp, strings

Alyona and the Tree

dfs and similar, dp, graphs, trees

Runaway to a Shadow

geometry, sortings

Gifts by the List

constructive algorithms, dfs and similar, graphs, trees

Heap Operations

constructive algorithms, data structures, greedy

Bear and Bad Powers of 42

data structures

Bear and Chase

brute force, dfs and similar, graphs, implementation, math, probabilities

Bear and Square Grid

dfs and similar, dsu, implementation

Bear and Tower of Cubes

binary search, dp, greedy

Lena and Queries

data structures, divide and conquer, geometry

Another Sith Tournament

bitmasks, dp, math, probabilities

Iterated Linear Function

math, number theory

Joty and Chocolate

implementation, math, number theory

The Same Calendar

implementation

Vanya and Balloons

binary search, brute force, dp, implementation

Vanya and Treasure

data structures, dp, graphs, shortest paths

The Last Fight Between Human and AI

math

Theseus and labyrinth

graphs, implementation, shortest paths

Trains and Statistic

data structures, dp, greedy

Tree Construction

data structures, trees

Money Transfers

constructive algorithms, data structures, greedy, sortings

Organizing a Race

data structures, greedy

Roads in Yusland

data structures, dp, greedy

Ultimate Weirdness of an Array

data structures, number theory

Robin Hood

binary search, greedy

Recycling Bottles

dp, geometry, greedy, implementation

Restore a Number

brute force, constructive algorithms, strings

Correct Bracket Sequence Editor

data structures, dsu, strings

Forensic Examination

data structures, string suffix structures

Chain Reaction

brute force, geometry

Codeword

combinatorics, strings

World Tour

graphs, shortest paths

Reberland Linguistics

dp, implementation, strings

Four Divisors

data structures, dp, math, number theory, sortings, two pointers

Beautiful Subarrays

data structures, divide and conquer, strings, trees

Simple Subset

constructive algorithms, greedy, number theory

Buses Between Cities

implementation

Rebus

constructive algorithms, expression parsing, greedy, math

To Hack or not to Hack

brute force, dp, greedy

International Olympiad

constructive algorithms, greedy, implementation, math

Binary Table

bitmasks, brute force, divide and conquer, dp, fft, math

Graph Coloring

dfs and similar, graphs

Gambling Nim

bitmasks, math, matrices, probabilities

Rotate Matrix

*special problem

Hungarian Notation

*special problem

Primes in Interval

*special problem

Divisibility Check

*special problem

Maximal Difference

*special problem

Array Sum

*special problem

Seasons

*special problem

Bear and Bowling 4

binary search, data structures, divide and conquer, geometry, ternary search