Eri and Expanded Sets

data structures, divide and conquer, math, number theory, two pointers

Alter the GCD

binary search, data structures, divide and conquer, implementation, number theory

Turtle and Inversions (Hard Version)

brute force, data structures, divide and conquer, dp, greedy, math, two pointers

Turtle and Inversions (Easy Version)

brute force, divide and conquer, dp, greedy, math

Guess The Tree

binary search, brute force, dfs and similar, divide and conquer, dsu, greedy, interactive, trees

Eliminating Balls With Merging (Hard Version)

binary search, brute force, data structures, divide and conquer, greedy, implementation

Eliminating Balls With Merging (Easy Version)

binary search, brute force, data structures, divide and conquer, greedy

Level Up

binary search, brute force, data structures, divide and conquer, implementation

Polygonal Segments

brute force, data structures, divide and conquer, dp, greedy, two pointers

Catch the Mole(Hard Version)

binary search, data structures, dfs and similar, divide and conquer, interactive, trees

Simultaneous Coloring

dfs and similar, divide and conquer, graphs

Range Minimum Sum

binary search, brute force, data structures, divide and conquer, implementation

Spinning Round (Hard Version)

divide and conquer, dp, trees

Spinning Round (Easy Version)

divide and conquer, dp, trees

Swap Dilemma

constructive algorithms, data structures, divide and conquer, greedy, math, sortings

Number of k-good subarrays

bitmasks, brute force, combinatorics, divide and conquer, dp, math, meet-in-the-middle

Invertible Bracket Sequences

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

Set

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

Unique Array

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

Frequency Mismatch (Easy Version)

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

Nene and the Mex Operator

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

No Palindromes

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

Burenka and Pether

*special problem, data structures, dfs and similar, divide and conquer, dsu, graphs, sortings, trees

Yet Yet Another Permutation Problem

divide and conquer, fft, math

Sum over all Substrings (Hard Version)

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

Increasing Subsequences

bitmasks, constructive algorithms, divide and conquer, greedy, math

Mischievous Shooter

brute force, data structures, divide and conquer, dp, implementation

Tree LGM

constructive algorithms, divide and conquer, games, trees

ace5 and Task Order

constructive algorithms, divide and conquer, implementation, interactive, probabilities, sortings

Optimizations From Chelsu

divide and conquer, dp, number theory, trees

Greetings

data structures, divide and conquer, sortings

Array Collapse

data structures, divide and conquer, dp, trees

Blueprint for Seating

combinatorics, divide and conquer, math

Deck-Building Game

divide and conquer, math

Field Should Not Be Empty

brute force, data structures, divide and conquer

Set To Max (Hard Version)

constructive algorithms, data structures, divide and conquer, greedy, implementation, sortings

Maximum And Queries (hard version)

bitmasks, divide and conquer, dp, greedy

Trees and XOR Queries Again

data structures, dfs and similar, divide and conquer, graphs, implementation, math, trees

Vova Escapes the Matrix

brute force, dfs and similar, divide and conquer, shortest paths

Cyclic Hamming (Easy Version)

brute force, divide and conquer, dp, fft, math, number theory

Ones and Twos

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

Split

binary search, data structures, divide and conquer, dsu, math, trees, two pointers

Sum of XOR Functions

bitmasks, combinatorics, divide and conquer, dp, math

Jellyfish and Miku

divide and conquer, dp, math, probabilities

Teleportation in Byteland

data structures, dfs and similar, divide and conquer, graphs, shortest paths, trees

Counting Graphs

combinatorics, divide and conquer, dsu, graphs, greedy, sortings, trees

More Wrong

divide and conquer, interactive

XOR Partition

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

Max to the Right of Min

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

Vika and Wiki

binary search, bitmasks, combinatorics, divide and conquer, dp, math

Omsk Metro (hard version)

data structures, dfs and similar, divide and conquer, dp, math, trees

Tenzing and Necklace

divide and conquer, dp, greedy

Half-sum

brute force, divide and conquer, greedy

Communication Towers

brute force, divide and conquer, dsu

Minibuses on Venus (medium version)

combinatorics, divide and conquer, dp, matrices

Minibuses on Venus (easy version)

combinatorics, divide and conquer, dp

Approximate Diameter

binary search, divide and conquer, graphs, shortest paths

Gasoline prices

data structures, divide and conquer, dsu, hashing, trees

Li Hua and Path

data structures, dfs and similar, divide and conquer, dsu, trees

Counting Factorizations

combinatorics, divide and conquer, dp, math, number theory

Rebrending

brute force, data structures, divide and conquer, implementation

Graph Coloring (hard version)

brute force, combinatorics, divide and conquer, dp, fft, graphs

Timofey and Black-White Tree

brute force, dfs and similar, divide and conquer, graphs, greedy, math, shortest paths, trees

Treasure Hunt

data structures, divide and conquer, two pointers

Weighed Tree Radius

data structures, divide and conquer, implementation, trees

Comfortably Numb

bitmasks, data structures, divide and conquer, strings, trees

BinCoin

binary search, divide and conquer, hashing, implementation, probabilities, trees

Koxia and Bracket

divide and conquer, fft, math

Decomposition

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

Bracket Cost

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

Yet Another Array Counting Problem

binary search, data structures, divide and conquer, dp, flows, math, trees

Masha and a Beautiful Tree

dfs and similar, divide and conquer, graphs, sortings, trees

Arranging Crystal Balls

data structures, divide and conquer, divide and conquer, dp, geometry, graphs, number theory

Zeros and Ones

bitmasks, divide and conquer, dp, math

Maximums and Minimums

combinatorics, data structures, divide and conquer, number theory

Maximum AND

bitmasks, dfs and similar, divide and conquer, greedy, sortings

Swap and Maximum Block

bitmasks, data structures, dfs and similar, divide and conquer, dp

Long Way Home

data structures, divide and conquer, dp, geometry, graphs, greedy, shortest paths

Qpwoeirut and Vertices

binary search, data structures, dfs and similar, divide and conquer, dsu, greedy, trees

Permutation Graph

binary search, constructive algorithms, data structures, divide and conquer, greedy, shortest paths

Decinc Dividing

brute force, data structures, divide and conquer, dp, greedy

Max GEQ Sum

binary search, constructive algorithms, data structures, divide and conquer, implementation, two pointers

Hard Cut

constructive algorithms, dfs and similar, divide and conquer, math

Unique Occurrences

data structures, dfs and similar, divide and conquer, dp, dsu, trees

Lenient Vertex Cover

dfs and similar, divide and conquer, dsu, graphs, trees

Maximum Crossings (Hard Version)

data structures, divide and conquer, sortings

Anti-Theft Road Planning

bitmasks, constructive algorithms, divide and conquer, greedy, interactive, math

Preorder

combinatorics, divide and conquer, dp, dsu, hashing, sortings, trees

MinimizOR

bitmasks, brute force, data structures, divide and conquer, greedy, implementation, two pointers

Mike's Sequence

*special problem, divide and conquer, implementation, math

Three Minimums

combinatorics, constructive algorithms, divide and conquer, dp, fft, math

Minimal String Xoration

bitmasks, data structures, divide and conquer, greedy, hashing, sortings, strings

Air Reform

data structures, dfs and similar, divide and conquer, dsu, graphs, implementation, trees

Serious Business

data structures, divide and conquer, dp, implementation, shortest paths

Special Positions

combinatorics, divide and conquer, fft, math

Perfect Matching

data structures, divide and conquer, interactive, trees

Cats on the Upgrade (easy version)

brute force, data structures, dfs and similar, divide and conquer, dp, graphs, trees

Permutation and Queries

brute force, data structures, divide and conquer, two pointers

Keep XOR Low

bitmasks, combinatorics, data structures, divide and conquer, dp, math

Reindeer Games

binary search, constructive algorithms, data structures, divide and conquer, flows, graphs, shortest paths