The Number of Pairs

dp, math, number theory

Minimum Grid Path

brute force, data structures, greedy, math

Binary Removals

brute force, dp, greedy, implementation

Domino on Windowsill

combinatorics, constructive algorithms, math

Christmas Game

bitmasks, data structures, dfs and similar, dp, games, math, trees

Two Houses

brute force, graphs, greedy, interactive, sortings

Bananas in a Microwave

dfs and similar, dp, graphs, implementation

Planar Reflections

brute force, data structures, dp

Box Fitting

binary search, bitmasks, data structures, greedy

GCD Sum

brute force, math

Square-Free Division (hard version)

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

Square-Free Division (easy version)

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

Genius

bitmasks, dp, graphs, number theory

k-LCM (hard version)

constructive algorithms, math

k-LCM (easy version)

constructive algorithms, math

M-arrays

constructive algorithms, greedy, math

Meximization

brute force, data structures, greedy, sortings

Max and Mex

math

Split it!

brute force, constructive algorithms, greedy, strings

Squares

constructive algorithms, data structures, dp, graphs, trees

Qingshan and Daniel

brute force, data structures, greedy, implementation

BFS Trees

combinatorics, dfs and similar, graphs, math, shortest paths, trees

Garden of the Sun

constructive algorithms, graphs

Let's Go Hiking

games, greedy

Diamond Miner

geometry, greedy, math, sortings

Delete The Edges

brute force, constructive algorithms, dfs and similar, graphs, implementation

A-Z Graph

constructive algorithms, data structures, graphs, hashing

Dogeforces

constructive algorithms, data structures, dfs and similar, divide and conquer, dsu, greedy, sortings, trees

1D Sokoban

binary search, dp, greedy, implementation, two pointers

Berland Crossword

bitmasks, brute force, greedy, implementation

ABC String

bitmasks, brute force, implementation

Enchanted Matrix

bitmasks, interactive, number theory

Enormous XOR

bitmasks, constructive algorithms, greedy, math, strings, two pointers

GCD of an Array

brute force, data structures, hashing, implementation, math, number theory, sortings, two pointers

K-beautiful Strings

binary search, brute force, constructive algorithms, greedy, strings

Planet Lapituletti

brute force, implementation

Anti-knapsack

constructive algorithms, greedy

Almost Fault-Tolerant Database

brute force, constructive algorithms, dfs and similar, greedy, implementation

Genius's Gambit

bitmasks, constructive algorithms, greedy, math

Maximum width

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

Card Deck

data structures, greedy, math

Three swimmers

math

Ruler Of The Zoo

brute force, data structures

Yuezheng Ling and Dynamic Tree

data structures, trees

Switch and Flip

constructive algorithms, graphs, math

Magnets

binary search, constructive algorithms, interactive

Fib-tree

brute force, dfs and similar, divide and conquer, number theory, trees

Zookeeper and The Infinite Zoo

bitmasks, constructive algorithms, dp, greedy, math

Pekora and Trampoline

brute force, data structures, dp, greedy, implementation

Minimal Cost

brute force, math

K-th Largest Value

brute force, greedy, implementation

Old Floppy Drive

binary search, data structures, math

Equalize the Array

binary search, data structures, greedy, math, sortings

Accidental Victory

binary search, data structures, greedy

Permutation Transformation

dfs and similar, divide and conquer, implementation

Sum of Cubes

binary search, brute force, brute force, math

Balanced Remainders

brute force, constructive algorithms, math

Dense Array

greedy, math

Flower Shop

*special problem, data structures, fft, math

Demonic Invasion

*special problem, flows

Build From Suffixes

*special problem, combinatorics, data structures

Painting Numbers

*special problem, data structures, greedy, number theory

Dogecoin

*special problem, *special problem, binary search, data structures

Palindromic Doubles

*special problem, data structures, dp

Problemsolving Marathon

*special problem, binary search, greedy

Two Policemen

*special problem, binary search, brute force, math

RBS Deletion

*special problem, greedy

From Zero To Y

*special problem, math

String Counting

combinatorics, dp, fft, math

Ones

dp, greedy, shortest paths

Cheap Dinner

brute force, data structures, graphs, greedy, implementation, sortings, two pointers

Pythagorean Triples

binary search, brute force, math, number theory

Minimum Ties

brute force, constructive algorithms, dfs and similar, graphs, greedy, implementation, math

Cat Cycle

math, number theory

Arena

implementation, sortings

Pairs of Paths

combinatorics, data structures, dfs and similar, dp, trees

Paired Payment

binary search, brute force, constructive algorithms, dp, flows, graphs, shortest paths

Max Median

binary search, data structures, dp

Guessing the Greatest (hard version)

binary search, interactive

Guessing the Greatest (easy version)

binary search, interactive

Eastern Exhibition

binary search, geometry, shortest paths, sortings

Shifting Stacks

greedy, implementation

Copy or Prefix Sum

combinatorics, data structures, dp, sortings

Move and Swap

dfs and similar, dp, greedy, trees

Multiples and Power Differences

constructive algorithms, graphs, math, number theory

Floor and Mod

binary search, brute force, math, number theory

Replace and Keep Sorted

dp, implementation, math

Add and Divide

brute force, greedy, math, number theory

Exam

data structures, string suffix structures, trees

Vabank

binary search, interactive

Useful Edges

graphs, shortest paths

Skyline Photo

data structures, divide and conquer, dp

Playlist

data structures, dsu, implementation, shortest paths

Basic Diplomacy

brute force, constructive algorithms, greedy, implementation

Restore Modulo

implementation, math

Prison Break

math

AB Tree

dp, greedy, trees

Sorting Books

data structures, dp, greedy

AB Graph

brute force, constructive algorithms, graphs, greedy, implementation

Fence Painting

brute force, constructive algorithms, greedy