Love-Hate

bitmasks, brute force, dp, probabilities

Nastia Plays with a Tree

constructive algorithms, data structures, dfs and similar, dp, dsu, greedy, implementation, trees

Baby Ehab Plays with Permutations

combinatorics, dp, math

Cut

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

Phoenix and Computers

combinatorics, dp, math

Colorings and Dominoes

combinatorics, dp, greedy, math

Digits

dp, math, number theory

Travelling Salesman Problem

binary search, data structures, dp, greedy, shortest paths, sortings, two pointers

Diameter Cuts

combinatorics, dfs and similar, dp, trees

Chaotic Merge

combinatorics, dp, math, strings

The Number of Pairs

dp, math, number theory

Christmas Game

bitmasks, data structures, dfs and similar, dp, games, math, trees

Bananas in a Microwave

dfs and similar, dp, graphs, implementation

Square-free division (hard version)

data structures, dp, greedy, math, number theory, two pointers

Genius

bitmasks, dp, graphs, number theory

Palindromic Doubles

*special problem, data structures, dp

Paired Payment

binary search, brute force, constructive algorithms, dp, flows, graphs, shortest paths

Max Median

binary search, data structures, dp

Copy or Prefix Sum

combinatorics, data structures, dp, sortings

Move and Swap

dfs and similar, dp, greedy, trees

Skyline Photo

data structures, divide and conquer, dp

Sorting Books

data structures, dp, greedy

Painting the Array II

constructive algorithms, data structures, dp, greedy, implementation

Cleaning

data structures, dp, greedy, math

Moving to the Capital

dfs and similar, dp, graphs, shortest paths

New Year's Puzzle

brute force, dp, graph matchings, greedy, sortings

LaIS

data structures, dp, greedy

Distinctive Roots in a Tree

data structures, dfs and similar, dp, trees

Sum of Paths

combinatorics, dp, math

Dog Snacks

binary search, dfs and similar, dp, greedy, trees

Two Editorials

brute force, dp, greedy, sortings, two pointers

Xor Tree

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

Make It Increasing

binary search, constructive algorithms, data structures, dp, implementation

Zero Remainder Sum

dp

Number Deletion Game

*special problem, dp, games, greedy

Fruit Sequences

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

Danger of Mad Snakes

combinatorics, dp, math

Bubble Cup hypothesis

bitmasks, constructive algorithms, dp, math

Battle Lemmings

dp, greedy

Pokémon Army (hard version)

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

Subsequences of Length Two

dp, strings

Egor in the Republic of Dagestan

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

Discrete Centrifugal Jumps

data structures, dp, graphs

Clear the Multiset

data structures, divide and conquer, dp, greedy

Yet Another Segments Subset

data structures, dp, graphs, sortings

Controversial Rounds

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

Monster Invaders

dp, greedy, implementation

Rarity and New Dress

dfs and similar, dp, implementation, shortest paths

Village (Minimum)

*special problem, dp, greedy, trees

Graph

*special problem, binary search, dfs and similar, dp, math, ternary search

Koa and the Beach (Hard Version)

constructive algorithms, dp, greedy, implementation

Sum of Digits

brute force, constructive algorithms, dp, greedy

Omkar and Circle

brute force, dp, games, greedy

Asterism (Hard Version)

binary search, combinatorics, dp, math, number theory, sortings

Flying Sort (Hard Version)

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

Flying Sort (Easy Version)

dp, greedy, two pointers

Two Arrays

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

Summoning Minions

constructive algorithms, dp, flows, graph matchings, greedy, sortings

Graph Coloring

dfs and similar, dp, graphs

Decreasing Heights

brute force, dp

Phoenix and Berries

brute force, dp, greedy, math

Nastya and Unexpected Guest

dfs and similar, dp, graphs, shortest paths

Kaavi and Magic Spell

dp, strings

Strange Function

binary search, data structures, dp, greedy

Independent Set

dfs and similar, dp, trees

AND Segments

bitmasks, combinatorics, data structures, dp, two pointers

Team Building

bitmasks, dp, greedy, sortings

Happy New Year

bitmasks, dp, implementation

Array Shrinking

dp, greedy

Tourism

dp, graphs, probabilities

Double Elimination

dp, implementation

Cow and Treats

binary search, combinatorics, dp, greedy, implementation, math

Animal Observation (hard version)

data structures, dp, greedy

Animal Observation (easy version)

data structures, dp

Erase Subsequences

dp, strings

Nanosoft

binary search, data structures, dp, implementation

Xenon's Attack on the Gangs

combinatorics, dfs and similar, dp, greedy, trees

Delete a Segment

brute force, constructive algorithms, data structures, dp, graphs, sortings, trees, two pointers

Miss Punyverse

dp, greedy, trees

Two Bracket Sequences

dp, strings, two pointers

Common Number

binary search, combinatorics, dp, math

Portals

data structures, dp, greedy, implementation, sortings

Beautiful Mirrors

data structures, dp, math, probabilities

Economic Difficulties

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

Tournament

brute force, dp, greedy

Antenna Coverage

data structures, dp, greedy, sortings

Tiling Terrace

brute force, dp

Cleaning Robots

dp, trees

Voting (Easy Version)

data structures, dp, greedy

Discarding Game

dp, greedy, two pointers

Maximum Weight Subset

dp, trees

Daniel and Spring Cleaning

bitmasks, brute force, combinatorics, dp

Hyakugoku and Ladders

dp, probabilities, shortest paths

Sum Balance

bitmasks, dfs and similar, dp, graphs

The Maximum Subtree

dfs and similar, dp, graphs, trees

Keyboard Purchase

bitmasks, dp

Balanced Binary Search Trees

dp, math

Alice and the Unfair Game

binary search, data structures, dp, dsu

Yet Another Substring Reverse

bitmasks, dp

Another Filling the Grid

combinatorics, dp, math