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

Seollal

graphs

New Year and Social Network

data structures, graph matchings, graphs, math, trees

New Year and Castle Construction

combinatorics, geometry, math, sortings

The Cake Is a Lie

constructive algorithms, data structures, dfs and similar, graphs

Intergalactic Sliding Puzzle

combinatorics, constructive algorithms, math

Kirchhoff's Current Loss

math

Miss Punyverse

dp, greedy, trees

New Year and Handle Change

binary search, dp

New Year Permutations

combinatorics, dp

Cards

combinatorics, dp, math, number theory, probabilities

Asterisk Substrings

string suffix structures

Four Stones

constructive algorithms

Tree Elimination

dp, trees

Divide The Students

brute force

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

Happy Cactus

dp

Invertation in Tournament

brute force, divide and conquer, graphs, 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

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

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

Send Tree to Charlie

combinatorics, dfs and similar, dsu, trees

Tree Queries

data structures, probabilities, trees

Cheap Robot

binary search, dsu, graphs, shortest paths, trees

Mission Possible

Regular Forestation

hashing, trees

Find String in a Grid

data structures, dp, strings, trees

Red-White Fence

combinatorics, fft

Voting (Hard Version)

binary search, data structures, greedy

SmartGarden

constructive algorithms, divide and conquer

Projectors

flows, graphs

Show Must Go On

binary search, brute force, greedy, shortest paths

Conference Problem

dp

Cursor Distance

Running in Pairs

constructive algorithms, greedy, math

Planar Perimeter

constructive algorithms, graphs

Number Discovery

math

Sum Balance

bitmasks, dfs and similar, dp, graphs

Football

graphs

Swiper, no swiping!

graphs, implementation

Turtle

dp, implementation

Catowice City

2-sat, dfs and similar, graph matchings, graphs

The World Is Just a Programming Task (Hard Version)

implementation

Adilbek and the Watering System

data structures, greedy, sortings

Balanced Reversals

constructive algorithms

Balanced Distribution

data structures, dp, greedy

Balanced Domino Placements

combinatorics, dp

Balanced Binary Search Trees

dp, math

Alice and the Cactus

dfs and similar, graphs, math, probabilities

Alice and the Unfair Game

binary search, data structures, dp, dsu

One Node is Gone

constructive algorithms, implementation, trees

Not Same

constructive algorithms

Wrong Answer on test 233 (Hard Version)

combinatorics, math

To Make 1

bitmasks, constructive algorithms, dp, greedy, number theory

Tree Factory

constructive algorithms, greedy, trees

Wooden Raft

binary search, math, number theory

Stack Exterminable Arrays

data structures, divide and conquer, dp, hashing

Graph And Numbers

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

Choose a Square

binary search, data structures, sortings

Game With String

games

Geolocation

geometry

Gardener Alex

binary search, data structures

Function Composition

dfs and similar

Alpha planetary system

constructive algorithms, graphs, shortest paths

Product Tuples

divide and conquer, fft

Xor Spanning Tree

divide and conquer, fft, graphs

Jumping Transformers

dp

Guarding warehouses

data structures, geometry

BubbleReactor

dp, graphs

Forced Online Queries Problem

data structures, divide and conquer, dsu, graphs, trees

Radio Stations

2-sat

Tiles Placement

constructive algorithms, dfs and similar, trees

Feeling Good

bitmasks, data structures

Employment

greedy, sortings