Animal Observation (easy version)

data structures, dp

1-Trees and Queries

data structures, dfs and similar, shortest paths, trees

Sum of Prefix Sums

data structures, divide and conquer, geometry, trees

Number of Components

dsu, implementation

Erase Subsequences

dp, strings

Super Jaber

dfs and similar, graphs, implementation, shortest paths

Nanosoft

binary search, data structures, dp, implementation

Time to Run

constructive algorithms, graphs, implementation

So Mean

interactive, math

Around the World

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

Water Balance

data structures, geometry, greedy

Berland Beauty

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

String Coloring (hard version)

data structures, dp

Good Contest

combinatorics, dp, probabilities

Permutation Separation

data structures, divide and conquer

Three Paths on a Tree

dfs and similar, dp, greedy, trees

Nora's Toy Boxes

bitmasks, combinatorics, dp

Rin and The Unknown Flower

constructive algorithms, greedy, interactive, math

Chaotic V.

dp, graphs, greedy, math, number theory, trees

Xenon's Attack on the Gangs

combinatorics, dfs and similar, dp, greedy, trees

Coffee Varieties (easy version)

graphs, interactive

Making Shapes

dp

Cartesian Tree

data structures

Coffee Varieties (hard version)

constructive algorithms, graphs, interactive

Prefix Enlightenment

dfs and similar, dsu, graphs

Red-Blue Graph

constructive algorithms, flows

Messenger Simulator

data structures

Minimax Problem

binary search, bitmasks, dp

Harry The Potter

brute force, constructive algorithms, dp, fft, implementation, math

Fedya the Potter Strikes Back

data structures, strings

LCC

data structures, math, matrices, probabilities

Madhouse (Hard version)

brute force, constructive algorithms, hashing, interactive, math

Madhouse (Easy version)

brute force, constructive algorithms, interactive, math

Classical?

binary search, combinatorics, number theory

Delete a Segment

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

Seollal

graphs

New Year and Social Network

data structures, graph matchings, graphs, math, trees

New Year and Castle Construction

combinatorics, geometry, math, sortings

New Year and Conference

binary search, data structures, hashing, sortings

DIY Garland

constructive algorithms, greedy, trees

The Cake Is a Lie

constructive algorithms, data structures, dfs and similar, graphs

Enchanted Artifact

constructive algorithms, interactive, strings

Intergalactic Sliding Puzzle

combinatorics, constructive algorithms, math

Kirchhoff's Current Loss

math

Miss Punyverse

dp, greedy, trees

Jeremy Bearimy

dfs and similar, graphs, greedy, trees

New Year and Handle Change

binary search, dp

New Year Permutations

combinatorics, dp

Cards

combinatorics, dp, math, number theory, probabilities

Tests for problem D

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

Segment Tree

data structures, dsu, graphs, trees

Asterisk Substrings

string suffix structures

Four Stones

constructive algorithms

Tree Elimination

dp, trees

Beautiful Rectangle

brute force, combinatorics, constructive algorithms, data structures, greedy, math

Two Bracket Sequences

dp, strings, two pointers

Divide The Students

brute force

Common Number

binary search, combinatorics, dp, math

Portals

data structures, dp, greedy, implementation, sortings

Xor on Figures

constructive algorithms, fft, math

Number of Components

data structures

Subset with Zero Sum

constructive algorithms, dfs and similar, graphs, math

Awesome Substrings

math, strings

Divide Points

constructive algorithms, geometry, math

Happy Cactus

dp

Invertation in Tournament

brute force, divide and conquer, graphs, math

K Integers

binary search, data structures

Domino for Young

dp, greedy, math

Key Storage

combinatorics, math

Intriguing Selection

brute force, constructive algorithms, implementation, interactive, sortings

Help BerLine

constructive algorithms

Game Relics

math, probabilities

Foolprüf Security

graphs

DevOps Best Practices

constructive algorithms

Cactus Revenge

constructive algorithms

Apprentice Learning Trajectory

Red-Blue Graph

dp, graphs, math, matrices, meet-in-the-middle

Permutation Concatenation

string suffix structures

Almost Same Distance

dfs and similar, graphs

Spaceship Solitaire

data structures, greedy, implementation

Decreasing Debts

constructive algorithms, data structures, graphs, greedy, implementation, math, two pointers

Beautiful Mirrors

data structures, dp, math, probabilities

Beautiful Fibonacci Problem

constructive algorithms, number theory

Beautiful League

constructive algorithms, flows, graph matchings

Beautiful Bracket Sequence (hard version)

combinatorics, probabilities

Beautiful Bracket Sequence (easy version)

combinatorics, dp, probabilities

Beautiful Mirrors with queries

data structures, probabilities

Economic Difficulties

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

Editor

data structures, implementation

Xor-Set

bitmasks, divide and conquer, math

Colored Tree

data structures, trees

Tournament

brute force, dp, greedy

Divisor Set

divide and conquer, fft, greedy, math, number theory

Make Them Similar

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

The Contest

data structures, dp, greedy

Equalizing Two Strings

constructive algorithms, sortings, strings

Yet Another Division Into Teams

dp, greedy, sortings

Send Tree to Charlie

combinatorics, dfs and similar, dsu, trees

Tree Queries

data structures, probabilities, trees

Point Ordering

constructive algorithms, geometry, interactive, math