Yunli's Subarray Queries (easy version)

binary search, data structures, two pointers

Sakurako's Test

binary search, brute force, greedy, math, number theory

Not a Nim Problem

brute force, games, math, number theory

Turtle and a MEX Problem (Hard Version)

dfs and similar, dp, graphs, greedy, implementation, math

DFS Checker (Easy Version)

brute force, data structures, dfs and similar, graphs, hashing, trees

Longest Max Min Subsequence

brute force, constructive algorithms, data structures, greedy, implementation

Call During the Journey

binary search, brute force, graphs, greedy, shortest paths

Color Rows and Columns

dp, greedy, implementation, math

Determine Winning Islands in Race

data structures, dp, graphs, greedy, shortest paths

Perform Operations to Maximize Score

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

Bomb

binary search, greedy, math

Wooden Game

bitmasks, greedy, math, trees

Funny Game

constructive algorithms, dsu, graphs, greedy, math, number theory, trees

Ultra-Meow

combinatorics, dp, math

Valuable Cards

brute force, dp, greedy, number theory, two pointers

Coloring Game

constructive algorithms, dfs and similar, games, graphs, greedy, interactive

Prime XOR Coloring

bitmasks, constructive algorithms, graphs, greedy, math, number theory

Smithing Skill

brute force, data structures, dp, greedy, math, sortings, two pointers

The Omnipotent Monster Killer

brute force, dfs and similar, dp, trees

Wonderful Tree!

brute force, data structures, dfs and similar, dsu, greedy, trees

Non-academic Problem

dfs and similar, graphs, trees

''a'' String Problem

brute force, hashing, implementation, math, string suffix structures, strings

Field Division (easy version)

data structures, math, sortings

Computing Machine

brute force, data structures, dp, greedy, implementation

Nikita and LCM

brute force, data structures, dp, greedy, math, number theory, sortings

Invertible Bracket Sequences

binary search, combinatorics, data structures, divide and conquer, implementation, two pointers

Chain Queries

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

Money Buys Less Happiness Now

data structures, greedy, sortings

Cutting Game

binary search, brute force, data structures, implementation, sortings, two pointers

±1

2-sat, dfs and similar, graphs

Min-Fund Prison (Easy)

dfs and similar, trees

Trails (Medium)

dp, matrices

Arithmancy (Easy)

brute force, constructive algorithms, interactive, strings

Game on Tree (Hard)

dfs and similar, dp, games, trees

Exact Neighbours (Medium)

constructive algorithms

Exact Neighbours (Easy)

constructive algorithms

Shop Game

data structures, greedy, math, sortings

Division + LCP (easy version)

binary search, data structures, dp, hashing, string suffix structures, strings

Narrow Paths

*special problem, combinatorics

Yet Another Permutation Constructive

*special problem, constructive algorithms

A BIT of an Inequality

bitmasks, brute force, dp, math

Nene and the Mex Operator

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

GCD on a grid

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

No Palindromes

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

Buying Jewels

constructive algorithms, greedy, math

Shuffling Songs

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

Annual Ants' Gathering

dfs and similar, dp, greedy, trees

Clique Partition

brute force, constructive algorithms, graphs, greedy, implementation

Birthday Gift

bitmasks, brute force, constructive algorithms, greedy, implementation

Kirill and Mushrooms

data structures, sortings

Non-Palindromic Substring

hashing, implementation, math, strings

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

There and Back Again

Bit Counting Sequence

Pinball

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

XOR Break --- Solo Version

bitmasks, constructive algorithms, greedy

Turtle Mission: Robot and the Earthquake

dfs and similar, dp, graphs, shortest paths

Feed Cats

data structures, dp, sortings

One-Dimensional Puzzle

combinatorics, math, number theory

Sum over all Substrings (Hard Version)

bitmasks, divide and conquer, dp, dsu, greedy, implementation, strings

Sasha and a Walk in the City

combinatorics, dp, math, trees

Lonely Mountain Dungeons

brute force, data structures, greedy, math, ternary search

Microcycle

data structures, dfs and similar, dsu, graphs, greedy, implementation, sortings, trees

Vlad and Trouble at MIT

dfs and similar, dp, flows, graphs, greedy, implementation, trees

Good Trip

combinatorics, dp, math, probabilities

Space Harbour

data structures, implementation, math, sortings

Count Paths

data structures, dfs and similar, dp, dsu, graphs, trees

Berserk Monsters

brute force, data structures, dsu, implementation, math

Sum of Progression

brute force, data structures, dp, implementation, math

Counting Binary Strings

combinatorics, dp, math

Array Repetition

binary search, brute force, dsu, implementation, math

Tree Diameter

interactive, trees

01 Tree

constructive algorithms, data structures, dsu, greedy, sortings, trees

Blocking Elements

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

Light Bulbs (Easy Version)

brute force, combinatorics, dfs and similar, dp, dsu, graphs, math, trees

Programming Competition

dfs and similar, dp, graph matchings, greedy, trees

Array Collapse

data structures, divide and conquer, dp, trees

Divisibility Test

math

Blueprint for Seating

combinatorics, divide and conquer, math

Accumulator Apex

data structures, implementation, sortings

Build Railway Stations

*special problem, greedy, trees

Maximum Sum Subarrays

*special problem, dp

Short Permutation Problem

combinatorics, dp, fft, math

Split Plus K

greedy, math, number theory

Count BFS Graph

combinatorics, dp

Maximize The Value

data structures, sortings

Merge Not Sort

constructive algorithms, dp

Cyclic MEX

data structures, implementation, math, two pointers

Geo Game

greedy, interactive, math

Collapsing Strings

data structures, strings, trees

Robot Queries

binary search, data structures, dp, implementation

Transitive Graph

dfs and similar, dp, dsu, graphs, implementation

Small GCD

bitmasks, brute force, dp, math, number theory

Unusual Entertainment

data structures, dfs and similar, dsu, shortest paths, sortings, trees, two pointers

Absolute Beauty

greedy, math

Permutation Sorting

data structures, sortings

XOR Construction

bitmasks, constructive algorithms, data structures, math, string suffix structures, trees

Freedom of Choice

brute force, greedy, implementation

A Growing Tree

data structures, dfs and similar, trees