Rollbacks (Hard Version)

data structures, interactive, trees

Rollbacks (Easy Version)

brute force, data structures, dfs and similar, trees

Trees and Segments

brute force, data structures, dp, greedy, two pointers

The Walkway

brute force, dp, greedy, math, number theory

Counting Graphs

combinatorics, divide and conquer, dsu, graphs, greedy, sortings, trees

Sum and Product

binary search, data structures, math

Power of Points

math, sortings

PermuTree (hard version)

bitmasks, dfs and similar, dp, fft, greedy, implementation, math, trees

PermuTree (easy version)

dfs and similar, dp, trees

More Wrong

divide and conquer, interactive

To Become Max

binary search, brute force, data structures, dp

Mark and Spaceship

brute force, dp

Game Bundles

brute force, constructive algorithms, dp, greedy, math

Michael and Hotel

binary search, interactive, trees

Expected Destruction

combinatorics, dp, math, probabilities

Earn or Unlock

bitmasks, brute force, dp

Dual (Hard Version)

constructive algorithms, math

Dual (Easy Version)

constructive algorithms, math

Panda Meetups

data structures, dp, flows

Rivalries

constructive algorithms, data structures, greedy

Miriany and Matchstick

constructive algorithms, dp, greedy

Ina of the Mountain

data structures, dp, greedy, math

Imbalanced Arrays

constructive algorithms, graphs, greedy, math, sortings, two pointers

Ntarsis' Set

binary search, math, number theory

Vlad and the Mountains

binary search, data structures, dsu, graphs, implementation, sortings, trees, two pointers

Lisa and the Martians

bitmasks, greedy, math, strings, trees

Nastya and Potions

dfs and similar, dp, graphs, sortings

The Third Letter

dfs and similar, dsu, graphs, greedy, implementation

The Morning Star

combinatorics, data structures, geometry, implementation, math, sortings

XOR Partition

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

Max to the Right of Min

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

Array Painting

constructive algorithms, greedy, two pointers

Binary String Copying

binary search, brute force, data structures, hashing, strings

Vika and Wiki

binary search, bitmasks, combinatorics, divide and conquer, dp, math

Vika and Stone Skipping

brute force, implementation, math, number theory

Vika and Bonuses

binary search, brute force, math, ternary search

Vika and Price Tags

math, number theory

The Boss's Identity

binary search, bitmasks, data structures, dfs and similar, greedy, math, sortings

Triangle Platinum?

brute force, combinatorics, implementation, interactive, math, probabilities

Professor Higashikata

data structures, dsu, greedy, implementation, strings

Vampiric Powers, anyone?

bitmasks, brute force, dp, greedy

Rudolf and CodeVid-23

bitmasks, dp, graphs, greedy, shortest paths

Rudolph and Mimic

constructive algorithms, implementation, interactive

Rudolf and Snowflakes (hard version)

binary search, brute force, implementation, math

Swimmers in the Pool

dp, fft, math, number theory

Boxes and Balls

dp, implementation, math

Rating System

binary search, brute force, data structures, dp, dsu, greedy, math, two pointers

Strong Password

binary search, dp, greedy, strings

Multiple of Three Cycles

combinatorics, data structures, dp, dsu, math

Tree Weights

bitmasks, constructive algorithms, data structures, dfs and similar, implementation, math, matrices, number theory, trees

Min Cost Permutation (Hard Version)

binary search, constructive algorithms, data structures, greedy, math, sortings

Min Cost Permutation (Easy Version)

brute force, constructive algorithms, greedy, math

Great Grids

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

Row Major

constructive algorithms, greedy, math, number theory, strings

Omsk Metro (hard version)

data structures, dfs and similar, divide and conquer, dp, math, trees

Omsk Metro (simple version)

data structures, dfs and similar, dp, graphs, greedy, math, trees

Tracking Segments

binary search, brute force, data structures, two pointers

Tenzing and Necklace

divide and conquer, dp, greedy

Tenzing and Random Real Numbers

bitmasks, dp, graphs, math, probabilities

Tenzing and Random Operations

combinatorics, dp, math, probabilities

Tenzing and Tree

dfs and similar, greedy, shortest paths, sortings, trees

Tenzing and Triangle

data structures, dp, geometry, greedy, math

Tenzing and His Animal Friends

constructive algorithms, graphs, greedy

Tenzing and Balls

dp

Monocarp and a Strategic Game

geometry, sortings, two pointers

Fill the Matrix

data structures, greedy, math

Pairs of Segments

data structures, greedy, sortings, two pointers

Ranom Numbers

brute force, dp, greedy, math, strings

In Search of Truth (Hard Version)

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

In Search of Truth (Easy Version)

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

Railguns

brute force, dfs and similar, dp, graphs

Character Blocking

data structures, hashing, implementation

Wooden Toy Festival

binary search, greedy, sortings

Decreasing Game

constructive algorithms, dfs and similar, dp, greedy, interactive

Ball Sorting

data structures, dp, sortings

Stuck Conveyor

binary search, constructive algorithms, interactive

Count Supersequences

combinatorics, dp, math

Bracket Walk

data structures, greedy, strings

No Prime Differences

constructive algorithms, math, number theory

Editorial for Two

binary search, data structures, greedy, implementation

Playoff Fixing

combinatorics, trees

Bracket Coloring

constructive algorithms, greedy

Good Graph

bitmasks, dfs and similar, graph matchings, graphs, implementation

Old Mobile

combinatorics, dp, probabilities

Doctor's Brown Hypothesis

dfs and similar, graphs, math, number theory

Twin Clusters

bitmasks, brute force, constructive algorithms, math, probabilities

Lottery

binary search, brute force, greedy, math, two pointers

k-th equality

brute force, implementation, math

Typewriter

brute force, math

MEX of LCM

binary search, data structures, implementation, math, number theory

Survey in Class

brute force, data structures, greedy, implementation, sortings

Ksyusha and Chinchilla

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

Ira and Flamenco

combinatorics, constructive algorithms, data structures, implementation, math, sortings, two pointers

Round Dance

dfs and similar, dsu, graphs, shortest paths

Flipper

brute force, constructive algorithms, greedy

Zombies

binary search, dp

Combinatorics Problem

brute force, combinatorics, dp

Red-Blue Operations (Hard Version)

binary search, constructive algorithms, greedy, implementation, math

Red-Blue Operations (Easy Version)

binary search, greedy, implementation, math

The Third Grace

data structures, dp