Diameter Cuts

combinatorics, dfs and similar, dp, trees

Chaotic Merge

combinatorics, dp, math, strings

The Number of Pairs

dp, math, number theory

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

Square-Free Division (hard version)

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

Genius

bitmasks, dp, graphs, number theory

Garden of the Sun

constructive algorithms, graphs

A-Z Graph

constructive algorithms, data structures, graphs, hashing

Dogeforces

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

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

Almost Fault-Tolerant Database

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

Fib-tree

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

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

Cheap Dinner

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

Paired Payment

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

Max Median

binary search, data structures, dp

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

Useful Edges

graphs, shortest paths

Skyline Photo

data structures, divide and conquer, dp

Sorting Books

data structures, dp, greedy

AB Graph

brute force, constructive algorithms, graphs, greedy, implementation

Continuous City

bitmasks, constructive algorithms

Painting the Array II

constructive algorithms, data structures, dp, greedy, implementation

Nezzar and Nice Beatmap

constructive algorithms, geometry, greedy, math, sortings

Pattern Matching

bitmasks, data structures, dfs and similar, graphs, hashing, sortings, strings

What Is It?

constructive algorithms, greedy

Cleaning

data structures, dp, greedy, math

Minimum Path

graphs, shortest paths

Moving to the Capital

dfs and similar, dp, graphs, shortest paths

New Year's Puzzle

brute force, dp, graph matchings, greedy, sortings

Strange Housing

constructive algorithms, dfs and similar, graph matchings, graphs, greedy

Strange Shuffle

binary search, brute force, constructive algorithms, interactive

A Bit Similar

bitmasks, brute force, hashing, string suffix structures, strings, two pointers

Similar Sets

data structures, graphs, implementation

Plane Tiling

geometry, implementation, math

K and Medians

constructive algorithms, greedy, math

Hobbits

binary search, geometry

LaIS

data structures, dp, greedy

Distinctive Roots in a Tree

data structures, dfs and similar, dp, trees

Sum of Paths

combinatorics, dp, math

Euclid's nightmare

bitmasks, dfs and similar, dsu, graphs, greedy, math, sortings

Plan of Lectures

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

Water Level

brute force, graphs, greedy, implementation, math

Glass Half Spilled

dp

Four Points

brute force, constructive algorithms, flows, geometry, greedy, implementation, math, ternary search

Array Partition

binary search, data structures, greedy, two pointers

Number of Simple Paths

combinatorics, dfs and similar, graphs, trees

Dog Snacks

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

Two Editorials

brute force, dp, greedy, sortings, two pointers

Bitwise Queries (Hard Version)

bitmasks, constructive algorithms, interactive, math

Bitwise Queries (Easy Version)

bitmasks, constructive algorithms, interactive, math

The Struggling Contestant

constructive algorithms, greedy

Errich-Tac-Toe (Hard Version)

constructive algorithms, math

Errich-Tac-Toe (Easy Version)

constructive algorithms, math

Xor Tree

binary search, bitmasks, data structures, divide and conquer, dp, trees

Team-Building

data structures, dfs and similar, dsu, graphs

Long Permutation

brute force, math, two pointers

Graph Transpositions

dfs and similar, graphs, greedy, shortest paths

Yurii Can Do Everything

binary search, bitmasks, brute force, constructive algorithms, divide and conquer, two pointers

Powerful Ksenia

bitmasks, constructive algorithms, math

Engineer Artem

2-sat, chinese remainder theorem, constructive algorithms, fft, flows

Make It Increasing

binary search, constructive algorithms, data structures, dp, implementation

Complicated Computations

binary search, data structures, two pointers

Reducing Delivery Cost

brute force, graphs, shortest paths

Zero Remainder Sum

dp

Number Deletion Game

*special problem, dp, games, greedy

Neural Network Problem

*special problem, binary search, greedy

Chess Match

*special problem

Fruit Sequences

binary search, data structures, divide and conquer, dp, two pointers

Carrots for Rabbits

binary search, data structures, greedy, math, sortings

Xum

bitmasks, constructive algorithms, math, matrices, number theory

Unshuffling a Deck

constructive algorithms, implementation

The Hard Work of Paparazzi

dp

Number of Subsequences

combinatorics, dp, strings

Excitation of Atoms

greedy, implementation

Danger of Mad Snakes

combinatorics, dp, math

Ancient Language

graphs, sortings

Bubble Cup hypothesis

bitmasks, constructive algorithms, dp, math

Virus

data structures, divide and conquer, dsu, graphs

Returning Home

graphs, shortest paths, sortings

Battle Lemmings

dp, greedy

Pokémon Army (hard version)

data structures, divide and conquer, dp, greedy, implementation

Decryption

constructive algorithms, implementation, math, number theory

Three Occurrences

data structures, divide and conquer, hashing, two pointers

Expected Damage

binary search, combinatorics, probabilities

Trash Problem

data structures, implementation

XOR Inverse

bitmasks, data structures, divide and conquer, dp, greedy, math, sortings, strings, trees

Make Them Equal

constructive algorithms, greedy, math

New Game Plus!

constructive algorithms, greedy, math

XOR-gun

bitmasks, brute force, constructive algorithms

Solo mid Oracle

greedy, math, ternary search

Poman Numbers

bitmasks, greedy, math, strings

Grime Zoo

brute force, greedy, implementation, strings