Connected Cubes

constructive algorithms, games

Missing Subarray Sum

constructive algorithms

Folding Strip

constructive algorithms, greedy, strings

Missing Subsequence Sum

bitmasks, constructive algorithms, greedy, number theory

Everything Nim

games, greedy, math, sortings

Necromancer

*special problem

Equal Trees

*special problem, graphs, meet-in-the-middle

Composite Spells

*special problem, dp

Observation Towers

*special problem

Narrow Paths

*special problem, combinatorics

Yet Another Permutation Constructive

*special problem, constructive algorithms

Staircase

*special problem

Firewood

*special problem

Clock in the Pool

*special problem, math

Frequency Mismatch (Hard Version)

binary search, data structures, dfs and similar, hashing, probabilities, trees

Frequency Mismatch (Easy Version)

binary search, data structures, divide and conquer, hashing, probabilities, trees

Carousel of Combinations

brute force, combinatorics, dp, math, number theory

A BIT of an Inequality

bitmasks, brute force, dp, math

How Does the Rook Move?

combinatorics, dp, math

Nene and the Passing Game

constructive algorithms, data structures, dsu, graphs, sortings

Nene vs. Monsters (Hard Version)

brute force, greedy, implementation, math

Nene vs. Monsters (Easy Version)

brute force, implementation, math

Nene and the Mex Operator

bitmasks, brute force, constructive algorithms, divide and conquer, dp, greedy, implementation, math

Nene's Magical Matrix

constructive algorithms, greedy, math

The Most Reckless Defense

bitmasks, brute force, constructive algorithms, dp, flows, graph matchings, shortest paths

GCD on a grid

brute force, dfs and similar, dp, implementation, math, number theory

Unfair Game

dp, games, greedy, math, schedules

Long Inversions

brute force, greedy, implementation, sortings

Inaccurate Subsequence Search

data structures, two pointers

Unique Strings

combinatorics, dp, math

Chain Reaction

binary search, data structures, dsu, greedy, implementation, math, number theory

Colored Balls

combinatorics, dp, math, sortings

Growing Trees

binary search, constructive algorithms, flows, graphs, greedy

Thanos Snap

binary search, dp, games, greedy, trees

Clacking Balls

combinatorics, math, probabilities

Inversion Composition

constructive algorithms, data structures, greedy

No Palindromes

brute force, constructive algorithms, divide and conquer, greedy, hashing, implementation, math, strings

Buying Jewels

constructive algorithms, greedy, math

Ticket Hoarding

greedy, math, sortings

Shuffling Songs

bitmasks, dfs and similar, dp, graphs, hashing, implementation, strings

0, 1, 2, Tree!

bitmasks, brute force, greedy, implementation, trees

Nearly Shortest Repeating Substring

brute force, implementation, number theory, strings

Make Triangle

constructive algorithms, math

Amanda the Amoeba

graphs, implementation, trees, two pointers

Disks

dfs and similar, geometry, graph matchings, graphs

Division Avoidance

greedy, math

Scooter

graphs, greedy

Dating

greedy, sortings, trees

Damage per Second

brute force, math

Funny or Scary?

constructive algorithms

Annual Ants' Gathering

dfs and similar, dp, greedy, trees

Charming Meals

binary search, brute force, greedy, sortings

Grove

brute force, dfs and similar, dp, geometry, probabilities

MST with Matching

bitmasks, brute force, dsu, graph matchings, trees

Rare Coins

combinatorics, math, probabilities

Clique Partition

brute force, constructive algorithms, graphs, greedy, implementation

Tandem Repeats?

brute force, strings, two pointers

Nobody is needed

2-sat, data structures, dfs and similar, dp

Girl Permutation

combinatorics, dp, math, number theory

Birthday Gift

bitmasks, brute force, constructive algorithms, greedy, implementation

Tree Cutting

binary search, dp, greedy, implementation, trees

GCD is Greater

brute force, data structures, math, number theory

Cook and Porridge

binary search, constructive algorithms, data structures, implementation

Kirill and Mushrooms

data structures, sortings

Binary Search

binary search, constructive algorithms, greedy

Minimum Hamming Distance

dp

MEX Game 2 (Hard Version)

binary search, greedy, two pointers

MEX Game 2 (Easy Version)

binary search, brute force, greedy

Counting Is Fun (Hard Version)

combinatorics, dp

Counting Is Fun (Easy Version)

brute force, combinatorics, dp, math

Tree Compass

constructive algorithms, dfs and similar, greedy, trees

Non-Palindromic Substring

hashing, implementation, math, strings

Farmer John's Favorite Intern

data structures, dp, flows, trees

Bessie and Cards

combinatorics, dp, math

Farmer John's Favorite Function

brute force, data structures, implementation, math

Farm Game

combinatorics, games

Learning to Paint

binary search, data structures, dfs and similar, dp, greedy, implementation, sortings

Bessie's Birthday Cake (Hard Version)

geometry, greedy, math

Rudolf and Subway

constructive algorithms, dfs and similar, graphs, shortest paths

Rudolf and Imbalance

binary search, greedy, sortings, two pointers

Rudolf and k Bridges

binary search, data structures, dp, two pointers

Zig-zag

XOR Operations

Tree Quiz

There and Back Again

Symmetric Boundary

Pho Restaurant

Personality Test

Forming Groups

Duplicates

Bánh Bò

Bit Counting Sequence

Attraction Score

Antiparticle Antiphysics

Grand Finale: Circles

binary search, geometry

Yet Yet Another Permutation Problem

divide and conquer, fft, math

Bitwise Paradox

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

Pokémon Arena

data structures, graphs, greedy, implementation, shortest paths, sortings

Pinball

binary search, data structures, implementation, math, two pointers

Bitwise Operation Wizard

bitmasks, constructive algorithms, greedy, interactive, math