Classical?

binary search, combinatorics, number theory

Mr. Kitayuta vs. Bamboos

binary search, greedy

Spaceship Exploration

binary search, geometry

Little Brother

binary search, geometry, sortings

Sasha and a Patient Friend

binary search, data structures, implementation

Local Deletions

binary search, data structures, implementation

Palindromic Problem

binary search, data structures, hashing, string suffix structures, strings

Shrink-Reverse

binary search, brute force, greedy, hashing, implementation, string suffix structures, strings

Forward, march!

binary search, dp, greedy

Min Cost Permutation (Hard Version)

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

Andrey's Tree

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

Nikita and game

binary search, dfs and similar, divide and conquer, graphs, trees

The Cells on the Paper

binary search, implementation, sortings

Long Way to be Non-decreasing

binary search, dfs and similar, graphs, implementation, shortest paths, two pointers

Au Pont Rouge

binary search, dp, strings

Rain of Fire

binary search, data structures, dfs and similar, dsu, graphs, implementation

Bear and Paradox

binary search, greedy, math, sortings

Cats on the Upgrade (hard version)

binary search, data structures, dfs and similar, graphs, trees

Hidden Bipartite Graph

binary search, constructive algorithms, dfs and similar, graphs, interactive

Karen and Cards

binary search, combinatorics, data structures, geometry

Tricky and Clever Password

binary search, constructive algorithms, data structures, greedy, hashing, strings

New Year and Handle Change

binary search, dp

NN country

binary search, data structures, trees

Pens And Days Of Week

*special problem, binary search, number theory

BCPC

binary search, geometry, two pointers

Colors

*special problem, binary search, constructive algorithms, interactive

Frequency Mismatch (Hard Version)

binary search, data structures, dfs and similar, hashing, probabilities, trees

Road to Home

binary search, dp

Prime Divisors Selection

binary search, greedy, math, number theory

Maximum Sine

binary search, data structures, number theory

You Are Given Some Letters...

binary search, implementation, math

Illumination

binary search, bitmasks, brute force, combinatorics, dp, math, two pointers

Omkar and Modes

binary search, divide and conquer, interactive

Tasty Cookie

binary search, constructive algorithms, greedy, implementation

Chess Strikes Back (easy version)

binary search, data structures

Baby Ehab's Hyper Apartment

binary search, graphs, interactive, sortings, two pointers

Jog Around The Graph

binary search, dp, geometry, graphs

Large Triangle

binary search, geometry, sortings

Jumping Around

binary search, data structures, divide and conquer, dp, dsu, graphs, shortest paths

Magician and Pigs (Hard Version)

binary search, brute force, data structures, implementation

Nastia and a Beautiful Matrix

binary search, constructive algorithms, dp, greedy

XOR Partition

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

k-substrings

binary search, hashing, string suffix structures

Gardener Alex

binary search, data structures

DZY Loves Planting

binary search, dsu, trees

Friends

binary search, bitmasks, data structures, math

Halve or Subtract

binary search, brute force, dp, greedy, sortings

Split

binary search, data structures, divide and conquer, dsu, math, trees, two pointers

Approximate Diameter

binary search, divide and conquer, graphs, shortest paths

Magnets

binary search, constructive algorithms, interactive

Distance Tree (hard version)

binary search, dfs and similar, shortest paths, trees

Résumé Review

binary search, greedy, math

Animals and Puzzle

binary search, data structures

The Hidden Pair (Hard Version)

binary search, dfs and similar, graphs, interactive, shortest paths, trees

Inna and Babies

binary search, data structures, dsu, geometry, implementation

Frequency Mismatch (Easy Version)

binary search, data structures, divide and conquer, hashing, probabilities, trees

Hot and Cold

binary search, interactive

Thoroughly Bureaucratic Organization

binary search, combinatorics

Two Friends

binary search, geometry

Teleporters

binary search, greedy

Good Pairs

binary search, data structures, dp

Find a Gift

binary search, interactive, probabilities

Preorder Test

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

Divan and a Cottage

binary search, data structures

Survival of the Weakest (easy version)

binary search, brute force, implementation, math, sortings

Power Sockets

binary search, data structures, greedy

Delivery Club

binary search, data structures, dp

Vasya and Big Integers

binary search, data structures, dp, hashing, strings

Boboniu and String

binary search, geometry, ternary search

Choosing Subtree is Fun

binary search, data structures, dfs and similar, trees, two pointers

Guard Towers

binary search, dsu, geometry, graphs, sortings

Velepin and Marketing

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

Parametric MST

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

Palindrome Partition

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

Zip-line

binary search, data structures, dp, hashing

Greedy Shopping

binary search, data structures, divide and conquer, greedy, implementation

Lucky Segments

binary search, implementation, two pointers

Packmen Strike Back

binary search, dp, math

Dividing Kingdom

binary search, brute force, data structures

Keen Tree Calculation

binary search, data structures, dp, geometry, graphs, implementation, trees

Strange Radiation

binary search, implementation, math

Cutting a Fence

binary search, data structures, dsu

New Year and Cleaning

binary search, implementation

Write The Contest

binary search, dp, math

Max and Bike

binary search, geometry

A Shade of Moonlight

binary search, geometry, math, sortings, two pointers

Sereja and Straight Lines

binary search, data structures, geometry, sortings, two pointers

Babysitting

2-sat, binary search, data structures, graphs, trees

Compute Power

binary search, dp, greedy

Cook and Porridge

binary search, constructive algorithms, data structures, implementation

Alice and the Unfair Game

binary search, data structures, dp, dsu

Volcanoes

binary search, implementation, sortings, two pointers

Round Marriage

binary search, graph matchings, greedy

Even Split

binary search, constructive algorithms, greedy, math

Traveling in Berland

binary search, data structures, graphs, greedy, implementation

Segments on the Line

binary search, dp

Misha and Palindrome Degree

binary search, combinatorics, implementation

Smile House

binary search, graphs, matrices

DZY Loves Strings

binary search, hashing, strings, two pointers

Hobbits

binary search, geometry