Hot Start Up (hard version)

data structures, dp

Lunar New Year and Red Envelopes

data structures, dp

Wi-Fi

data structures, dp, greedy

Counting Shortcuts

data structures, dfs and similar, dp, graphs, shortest paths

Red-Black Number

dfs and similar, dp, implementation, math, meet-in-the-middle

Counting Binary Strings

combinatorics, dp, math

Sum over all Substrings (Hard Version)

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

Neko and Aki's Prank

dp, greedy, trees

Learning to Paint

binary search, data structures, dfs and similar, dp, greedy, implementation, sortings

Perfect Groups

dp, math, number theory

You Are Given a WASD-string...

brute force, data structures, dp, greedy, implementation, math, strings

Colorings and Dominoes

combinatorics, dp, greedy, math

Count Binary Strings

data structures, dp

Paint the Tree

dp, sortings, trees

Shovels Shop

dp, greedy, sortings

Flexible String Revisit

combinatorics, dp, math, probabilities

Playlist for Polycarp (easy version)

bitmasks, combinatorics, dp

Breaking Good

dfs and similar, dp, graphs, shortest paths

Hossam and (sub-)palindromic tree

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

Speedrun

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

Game of Stones

bitmasks, dp, games

Preorder

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

Pathwalks

data structures, dp, graphs

Array Collapse

data structures, divide and conquer, dp, trees

Anya and Cubes

binary search, bitmasks, brute force, dp, math, meet-in-the-middle

Portals

data structures, dp, greedy, implementation, sortings

Tree with Small Distances

dp, graphs, greedy

Bear and Tree Jumps

dfs and similar, dp, trees

Counting Rhyme

dp, math, number theory

Mahmoud and a xor trip

bitmasks, constructive algorithms, data structures, dfs and similar, dp, math, trees

Increase Sequence

combinatorics, dp

How Many Paths?

dfs and similar, dp, graphs, trees

Pictures with Kittens (hard version)

data structures, dp

New Year's Puzzle

brute force, dp, graph matchings, greedy, sortings

Skyline Photo

data structures, divide and conquer, dp

Vasya and Beautiful Arrays

brute force, dp, number theory

Flying Sort (Easy Version)

dp, greedy, two pointers

Game on Sum (Easy Version)

combinatorics, dp, games, math

Sleepy Game

dfs and similar, dp, games, graphs

Number of Components

combinatorics, data structures, dp, math

Graph Coloring

dfs and similar, dp, graphs

Common Number

binary search, combinatorics, dp, math

Pencils and Boxes

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

Recovering BST

brute force, dp, math, number theory, trees

Beautiful Mirrors

data structures, dp, math, probabilities

Arena

combinatorics, dp, math

Xor Tree

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

Optimal Partition

data structures, dp

Watching Fireworks is Fun

data structures, dp, math

Divan and Kostomuksha (easy version)

dp, number theory

Anton and Tree

dfs and similar, dp, trees

Rarity and New Dress

dfs and similar, dp, implementation, shortest paths

Valid Sets

dfs and similar, dp, math, trees

Painting the Array II

constructive algorithms, data structures, dp, greedy, implementation

Two Arrays

binary search, brute force, combinatorics, constructive algorithms, dp, two pointers

Magic Gems

dp, math, matrices

Cut

binary search, data structures, dp, graphs, number theory, two pointers

Nearest Beautiful Number (hard version)

bitmasks, brute force, constructive algorithms, dfs and similar, dp, greedy

Subsequences of Length Two

dp, strings

Moving to the Capital

dfs and similar, dp, graphs, shortest paths

Pokémon Army (hard version)

data structures, divide and conquer, dp, greedy, implementation

Xor-Paths

bitmasks, brute force, dp, meet-in-the-middle

Kalila and Dimna in the Logging Industry

dp, geometry

Round Subset

dp, math

Police Stations

constructive algorithms, dfs and similar, dp, graphs, shortest paths, trees

Civilization

dfs and similar, dp, dsu, ternary search, trees

Omkar and Circle

brute force, dp, games, greedy

The Number of Pairs

dp, math, number theory

Array Shrinking

dp, greedy

Zero Remainder Sum

dp

A and B and Lecture Rooms

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

Max Median

binary search, data structures, dp

Tree Painting

dfs and similar, dp, trees