Tensor

constructive algorithms, graphs, interactive

XORificator

bitmasks, brute force, greedy, hashing

Mind Bloom

dp

378QAQ and Core

greedy, strings

Zimpha Fan Club

fft, greedy, math, strings

Set

bitmasks, brute force, combinatorics, dfs and similar, divide and conquer, dp, math

Chain Queries

binary search, data structures, dfs and similar, implementation, trees

Money Buys Less Happiness Now

data structures, greedy, sortings

Maximum GCD Sum Queries

bitmasks, brute force, dp, implementation, number theory

Cat, Fox and Swaps

graphs, math, sortings

Cat, Fox and Maximum Array Split

brute force, interactive, math

±1

2-sat, dfs and similar, graphs

Min-Fund Prison (Hard)

bitmasks, dfs and similar, dp, graphs, trees

Min-Fund Prison (Medium)

brute force, dfs and similar, dp, graphs, trees

Playing Quidditch (Hard)

implementation

Playing Quidditch (Medium)

implementation

Playing Quidditch (Easy)

implementation

Trails (Hard)

dp, matrices

Trails (Medium)

dp, matrices

Arithmancy (Hard)

interactive

Arithmancy (Medium)

constructive algorithms, interactive, probabilities, strings

Arithmancy (Easy)

brute force, constructive algorithms, interactive, strings

Exact Neighbours (Hard)

constructive algorithms

Exact Neighbours (Medium)

constructive algorithms

Balanced Unshuffle (Hard)

constructive algorithms, trees

Balanced Unshuffle (Medium)

brute force, constructive algorithms, trees

Card Pairing

dp, greedy, hashing, implementation

Unique Array

binary search, data structures, divide and conquer, dp, greedy

Division + LCP (hard version)

binary search, brute force, data structures, dp, hashing, math, string suffix structures, strings

Next and Prev

brute force, data structures, implementation

Again Counting Arrays (Hard Version)

combinatorics, dp, math

Again Counting Arrays (Easy Version)

combinatorics, dp, fft, math

Long Way to be Non-decreasing

binary search, dfs and similar, graphs, implementation, shortest paths, two pointers

Fenwick Tree

bitmasks, brute force, combinatorics, data structures, dp, math, trees

Reverse Card (Hard Version)

brute force, math, number theory

Conference

data structures, flows

Connected Cubes

constructive algorithms, games

Missing Subarray Sum

constructive algorithms

Folding Strip

constructive algorithms, greedy, strings

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

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

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

The Most Reckless Defense

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

Unique Strings

combinatorics, dp, math

Chain Reaction

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

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

Make Triangle

constructive algorithms, math

Amanda the Amoeba

graphs, implementation, trees, two pointers

Division Avoidance

greedy, math

Scooter

graphs, greedy

Dating

greedy, sortings, trees

Damage per Second

brute force, math

Funny or Scary?

constructive algorithms

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

Nobody is needed

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

Girl Permutation

combinatorics, dp, math, number theory

GCD is Greater

brute force, data structures, math, number theory

Cook and Porridge

binary search, constructive algorithms, data structures, implementation

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

Rudolf and Subway

constructive algorithms, dfs and similar, graphs, shortest paths

Zig-zag

XOR Operations

Tree Quiz

There and Back Again

Symmetric Boundary

Personality Test

Forming Groups

Duplicates

Bánh Bò

Attraction Score

Antiparticle Antiphysics

Grand Finale: Circles

binary search, geometry