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

Buying Jewels

constructive algorithms, greedy, math

Non-Palindromic Substring

hashing, implementation, math, strings

Rudolf and Subway

constructive algorithms, dfs and similar, graphs, shortest paths

Pinball

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

One-Dimensional Puzzle

combinatorics, math, number theory

Count Paths

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

Tree Diameter

interactive, trees

Build Railway Stations

*special problem, greedy, trees

Cyclic MEX

data structures, implementation, math, two pointers

Geo Game

greedy, interactive, math

Small GCD

bitmasks, brute force, dp, math, number theory

Freedom of Choice

brute force, greedy, implementation

A Growing Tree

data structures, dfs and similar, trees

Doremy's Drying Plan (Easy Version)

brute force, data structures, dp, greedy, sortings

Anya and the Mysterious String

binary search, data structures

Replace With Product

brute force, greedy, math

Salyg1n and Array (simple version)

constructive algorithms, interactive, math

The Great Equalizer

binary search, data structures, math, sortings

Counting Graphs

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

Vlad and the Mountains

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

Pairs of Segments

data structures, greedy, sortings, two pointers

The BOSS Can Count Pairs

brute force, math

Range Sorting (Easy Version)

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

Sum Graph

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

Accommodation

brute force, dp, greedy, implementation

Maximum Subarray

data structures, dp, greedy, two pointers

Moving Dots

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

Different Arrays

brute force, dp, implementation

Copy of a Copy of a Copy

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

Koxia and Game

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

Doremy's Pegging Game

combinatorics, dp, math

Another Array Problem

brute force, constructive algorithms, greedy

Wish I Knew How to Sort

dp, math, probabilities

MEX vs MED

math, two pointers

Multi-Colored Segments

binary search, data structures, math, sortings

Zero-One (Hard Version)

dp, greedy

Graph Cost

dp, greedy, math, number theory

Edge Split

brute force, constructive algorithms, dfs and similar, dsu, graphs, probabilities, trees

Circular Mirror

binary search, combinatorics, geometry, math, two pointers

Fibonacci Strings

greedy, implementation, math, number theory

Chip Move

brute force, dp, math

Robot in a Hallway

data structures, dp, greedy, implementation, ternary search

Empty Graph

binary search, constructive algorithms, data structures, greedy, shortest paths

Passable Paths (hard version)

data structures, dfs and similar, trees

Placing Jinas

combinatorics, math

Count the Trains

binary search, data structures, greedy, sortings

Linguistics

greedy, implementation, sortings, strings

Circular Spanning Tree

constructive algorithms, implementation, trees

Moving Chips

bitmasks, dp, greedy

Remove Directed Edges

dfs and similar, dp, graphs

Breaking the Wall

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

Array Shuffling

constructive algorithms, graphs, greedy

GCD Guess

bitmasks, chinese remainder theorem, constructive algorithms, games, interactive, math, number theory

For Gamers. By Gamers.

binary search, brute force, greedy, math, sortings

Weight the Tree

constructive algorithms, dfs and similar, dp, implementation, trees

Repetitions Decoding

constructive algorithms, implementation, sortings

Big Brush

constructive algorithms, data structures, greedy, implementation

Finding Zero

constructive algorithms, interactive, math

New Year Concert

binary search, data structures, greedy, math, number theory, two pointers

Interacdive Problem

binary search, constructive algorithms, interactive

Masha-forgetful

brute force, constructive algorithms, dp, hashing, implementation, strings

Shuffle

combinatorics, math, two pointers

Exact Change

brute force, constructive algorithms, greedy

Unusual Minesweeper

binary search, dfs and similar, dsu, greedy, sortings

Let's Play the Hat?

brute force, constructive algorithms, greedy, math

Reverse

bitmasks, constructive algorithms, dfs and similar, implementation, math, strings

Keep the Average High

dp, greedy, math

Crazy Robot

dfs and similar, graphs

Messages

brute force, dp, greedy, probabilities, sortings

Not Quite Lee

combinatorics, dp, math, number theory

Bubble Strike

combinatorics, math, probabilities, ternary search

Guess the Permutation

binary search, combinatorics, interactive, math

Pchelyonok and Segments

binary search, data structures, dp, greedy, math

The Strongest Build

binary search, brute force, data structures, dfs and similar, graphs, greedy, hashing, implementation

Kotlinforces

*special problem, constructive algorithms, dp

Expression Evaluation Error

constructive algorithms, greedy, implementation, math

Buds Re-hanging

constructive algorithms, dfs and similar, dp, greedy, trees

Bottom-Tier Reversals

constructive algorithms, greedy

Fixed Points

binary search, brute force, dp

Omkar and Medians

data structures, greedy, implementation

Robot Collisions

data structures, greedy, implementation, sortings

Nastia and a Hidden Permutation

constructive algorithms, interactive

Cut and Stick

binary search, data structures, greedy, implementation, sortings

GCD and MST

constructive algorithms, dsu, graphs, greedy, number theory, sortings

Maximize the Remaining String

brute force, data structures, dp, greedy, strings

Triangular Paths

constructive algorithms, graphs, math, shortest paths, sortings

K-beautiful Strings

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

Cheap Dinner

brute force, data structures, graphs, greedy, implementation, sortings, two pointers

AB Graph

brute force, constructive algorithms, graphs, greedy, implementation

Glass Half Spilled

dp

Number of Simple Paths

combinatorics, dfs and similar, graphs, trees

Bitwise Queries (Easy Version)

bitmasks, constructive algorithms, interactive, math

Engineer Artem

2-sat, chinese remainder theorem, constructive algorithms, fft, flows

Chess Match

*special problem

Unshuffling a Deck

constructive algorithms, implementation

The Hard Work of Paparazzi

dp

Number of Subsequences

combinatorics, dp, strings

XOR Inverse

bitmasks, data structures, divide and conquer, dp, greedy, math, sortings, strings, trees