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

Suspicious logarithms

binary search, brute force, math

Doremy's Drying Plan (Easy Version)

brute force, data structures, dp, greedy, sortings

Time Travel

binary search, graphs, shortest paths

Monocarp and the Set

combinatorics, data structures, math

Counting Rhyme

dp, math, number theory

Dances (Hard Version)

binary search, greedy, sortings, two pointers

Tree XOR

bitmasks, dfs and similar, dp, greedy, trees

Anya and the Mysterious String

binary search, data structures

Vasilije Loves Number Theory

brute force, math, number theory

Autosynthesis

constructive algorithms, dfs and similar, graphs, greedy, sortings

Replace With Product

brute force, greedy, math

Candy Party (Hard Version)

bitmasks, constructive algorithms, dp, greedy, implementation, math

Salyg1n and Array (simple version)

constructive algorithms, interactive, math

Happy Sets

combinatorics

Grouped Carriages

binary search, data structures, dp, flows, greedy

Completely Searching for Inversions

dfs and similar, dp, graphs

Guess Game

bitmasks, data structures, games, math, probabilities, sortings, strings, trees

Speedrun

brute force, dfs and similar, dp, graphs, greedy, math, sortings, two pointers

The Great Equalizer

binary search, data structures, math, sortings

Counting Graphs

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

More Wrong

divide and conquer, interactive

Dual (Hard Version)

constructive algorithms, math

Vlad and the Mountains

binary search, data structures, dsu, graphs, implementation, sortings, trees, two pointers

Professor Higashikata

data structures, dsu, greedy, implementation, strings

Rudolf and CodeVid-23

bitmasks, dp, graphs, greedy, shortest paths

Tenzing and His Animal Friends

constructive algorithms, graphs, greedy

Pairs of Segments

data structures, greedy, sortings, two pointers

Ball Sorting

data structures, dp, sortings

Bracket Walk

data structures, greedy, strings

Survey in Class

brute force, data structures, greedy, implementation, sortings

Red-Blue Operations (Easy Version)

binary search, greedy, implementation, math

The BOSS Can Count Pairs

brute force, math

Range Sorting (Easy Version)

binary search, dp, dsu, greedy, trees, two pointers

Unique Palindromes

constructive algorithms, math, strings

Rearrange Brackets

brute force, dp, greedy, sortings, strings

Black Cells

binary search, brute force, greedy, math

The Butcher

geometry, greedy, implementation, sortings, two pointers

Fish Graph

brute force, constructive algorithms, dfs and similar, graphs

Sum Graph

brute force, constructive algorithms, graphs, implementation, interactive, shortest paths, trees

Vlad and the Nice Paths (easy version)

combinatorics, dp, math

Is It Flower?

dfs and similar, graphs, implementation

Monsters

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

Petya, Petya, Petr, and Palindromes

binary search, brute force, data structures, two pointers

Unlucky Numbers

brute force, dp, greedy, implementation

Accommodation

brute force, dp, greedy, implementation

The way home

binary search, data structures, dp, graphs, greedy, shortest paths, sortings

Music Festival

binary search, data structures, dp, greedy, sortings

Dasha and Nightmares

bitmasks, hashing, meet-in-the-middle, strings

Hot Start Up (hard version)

data structures, dp

Hot Start Up (easy version)

dp

Li Hua and Tree

brute force, data structures, dfs and similar, dp, implementation, trees

Maximum Subarray

data structures, dp, greedy, two pointers

Counting Factorizations

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

Teleporters (Hard Version)

binary search, greedy, sortings

Timofey and Black-White Tree

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

Moving Dots

binary search, brute force, combinatorics, math, two pointers

The Harmonization of XOR

bitmasks, constructive algorithms, greedy, math

Game on Axis

combinatorics, dfs and similar, dsu, graphs, implementation

Letter Exchange

constructive algorithms

Different Arrays

brute force, dp, implementation

Flexible String Revisit

combinatorics, dp, math, probabilities

Score of a Tree

bitmasks, combinatorics, dfs and similar, dp, math, probabilities, trees

Another Wine Tasting Event

combinatorics, constructive algorithms, math, strings

The Human Equation

greedy, implementation

Two Chess Pieces

dfs and similar, dp, greedy, trees

King's Puzzle

constructive algorithms

Amazing Trick

constructive algorithms, graph matchings, math, probabilities

Copy of a Copy of a Copy

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

Hossam and (sub-)palindromic tree

brute force, data structures, dfs and similar, dp, strings, trees

Koxia and Game

constructive algorithms, data structures, dfs and similar, dsu, flows, games, graph matchings, graphs, implementation

Count Binary Strings

data structures, dp

Doremy's Pegging Game

combinatorics, dp, math

Another Array Problem

brute force, constructive algorithms, greedy

GCD Queries

constructive algorithms, interactive, number theory

Carry Bit

combinatorics, math

Restore the Permutation

binary search, constructive algorithms, data structures, greedy, math

Wish I Knew How to Sort

dp, math, probabilities

Counting Arrays

combinatorics, dp, math, number theory

ConstructOR

bitmasks, chinese remainder theorem, combinatorics, constructive algorithms, math, number theory

Yet Another Problem

binary search, bitmasks, constructive algorithms, data structures

Paths on the Tree

dfs and similar, dp, greedy, sortings, trees