One-Four Overload

2-sat, constructive algorithms, dfs and similar, dsu, graphs, implementation

Misha and Paintings

constructive algorithms, data structures, greedy, implementation, math

Beautiful League

constructive algorithms, flows, graph matchings

Johnny Solving

constructive algorithms, dfs and similar, graphs, math

Off by One

constructive algorithms, dfs and similar, geometry, graphs, sortings, trees

Nested Rubber Bands

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

Magnets

binary search, constructive algorithms, interactive

Nullify The Matrix

constructive algorithms, games

Zigu Zagu

constructive algorithms, data structures, greedy

Bags and Coins

bitmasks, constructive algorithms, dp, greedy

Foo Fighters

bitmasks, constructive algorithms

Common Divisor Graph

brute force, constructive algorithms, dsu, graphs, hashing, math, number theory

Capitalism

constructive algorithms, dfs and similar, graphs, shortest paths

Conveyor

constructive algorithms, dp, math

X-OR

bitmasks, constructive algorithms, divide and conquer, interactive, probabilities

Subset with Zero Sum

constructive algorithms, dfs and similar, graphs, math

Arithmancy (Medium)

constructive algorithms, interactive, probabilities, strings

Replicating Processes

constructive algorithms, greedy

Grocer's Problem

constructive algorithms, graphs, greedy

Doe Graphs

constructive algorithms, divide and conquer, dp, graphs, shortest paths

Odd Federalization

constructive algorithms

How to Learn You Score

constructive algorithms, interactive

Funny or Scary?

constructive algorithms

Berland Army

constructive algorithms, graphs, greedy

Upgrading Tree

constructive algorithms, dfs and similar, graphs, math, trees

Constrained Tree

constructive algorithms, data structures

Guess the String

constructive algorithms, interactive, probabilities

Triple Flips

constructive algorithms

Tricky Interactor

constructive algorithms, implementation, interactive

Button Pressing

bitmasks, constructive algorithms, hashing

Aztec Catacombs

constructive algorithms

Sum of Matchings

brute force, combinatorics, constructive algorithms, dfs and similar, graph matchings, greedy, math

Two Paths

constructive algorithms, dsu, graphs, implementation

Knights

constructive algorithms

Weights

constructive algorithms, greedy, two pointers

Bracket Xoring

constructive algorithms, greedy, implementation, math

Winding polygonal line

constructive algorithms, geometry, greedy, math

Intriguing Selection

brute force, constructive algorithms, implementation, interactive, sortings

Min Cost Permutation (Easy Version)

brute force, constructive algorithms, greedy, math

Alice and Recoloring 1

constructive algorithms, greedy

Matrix Sorting

bitmasks, brute force, constructive algorithms, greedy, two pointers

Counting Prefixes

combinatorics, constructive algorithms, dp, implementation, math

New Year and the Mallard Expedition

constructive algorithms, greedy

Nastya and Time Machine

constructive algorithms, dfs and similar, graphs, trees

Greedy Change

constructive algorithms

Guess Divisors Count

constructive algorithms, interactive, number theory

Colorful Constructive

constructive algorithms, data structures, greedy

Serega the Pirate

brute force, constructive algorithms

Puzzle

constructive algorithms, dp, greedy

Tree Recovery

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

Enormous XOR

bitmasks, constructive algorithms, greedy, math, strings, two pointers

Omkar and Akmar

chinese remainder theorem, combinatorics, constructive algorithms, fft, games, geometry, math, meet-in-the-middle, string suffix structures

Bring Balance

brute force, constructive algorithms, greedy

Colouring Game

constructive algorithms, dp, games

Twin Clusters

bitmasks, brute force, constructive algorithms, math, probabilities

Not Same

constructive algorithms

Flip the Cards

2-sat, constructive algorithms, data structures, greedy, sortings, two pointers

Parametric MST

binary search, constructive algorithms, graphs, greedy, math, sortings

Graph Subset Problem

constructive algorithms, data structures, graphs

Pairs of Pairs

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

Phoenix and Earthquake

constructive algorithms, dfs and similar, dsu, graphs, greedy, trees

Integer Game

constructive algorithms, games, interactive, math

Arpa’s overnight party and Mehrdad’s silent entering

constructive algorithms, dfs and similar, graphs

Mike and Fish

constructive algorithms, dfs and similar, graphs

Help Monks

constructive algorithms

HQ

*special problem, constructive algorithms

Deputies

constructive algorithms, graphs, greedy, implementation

Interactive Bulls and Cows (Hard)

brute force, constructive algorithms, interactive

Madness

constructive algorithms, dfs and similar, trees

SmartGarden

constructive algorithms, divide and conquer

The Evil Temple and the Moving Rocks

constructive algorithms

One Node is Gone

constructive algorithms, implementation, trees

Palindromic Parentheses

constructive algorithms

Yaroslav and Algorithm

constructive algorithms

Balance

constructive algorithms, dfs and similar, graphs, trees

Color the Carpet

constructive algorithms

Madoka and The First Session

constructive algorithms, flows, graph matchings, graphs, implementation

AND-permutations

constructive algorithms

CNF 2

constructive algorithms, dfs and similar, graphs, greedy

Inverse Transformation

constructive algorithms, implementation, math

Cook and Porridge

binary search, constructive algorithms, data structures, implementation

Inversion Composition

constructive algorithms, data structures, greedy

Degree Set

constructive algorithms, graphs, implementation

Even Split

binary search, constructive algorithms, greedy, math

Laboratory on Pluto

constructive algorithms, dp, greedy, math

XOR, Tree, and Queries

bitmasks, constructive algorithms, dfs and similar, dsu, graphs, greedy, implementation, trees

Max Sum Array

combinatorics, constructive algorithms, greedy, sortings

Dasha and Chess

constructive algorithms, games, interactive

Tree Factory

constructive algorithms, greedy, trees

Coloring

combinatorics, constructive algorithms, implementation, math

Construct Tree

bitmasks, constructive algorithms, dp, trees

In Search of Truth (Hard Version)

constructive algorithms, interactive, math, meet-in-the-middle, probabilities

Doremy's Experimental Tree

brute force, constructive algorithms, dfs and similar, dsu, sortings, trees

Game with Cards

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

Necklace

constructive algorithms, math

Summoning Minions

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

ANDfinity

bitmasks, brute force, constructive algorithms, dfs and similar, dsu, graphs

Picking Strings

constructive algorithms, implementation, strings

Almost Fault-Tolerant Database

brute force, constructive algorithms, dfs and similar, greedy, implementation

Add on a Tree: Revolution

constructive algorithms, dfs and similar, implementation, trees