Red and Blue Balls

Pages

implementation

Sorting Permutations

Instant Messanger

data structures

Tree and Array

constructive algorithms

Painting The Wall

dp, probabilities

Cards

constructive algorithms, implementation

On Corruption and Numbers

constructive algorithms, implementation, math

On Segment's Own Points

implementation

On Iteration of One Well-Known Function

math

On Sum of Number of Inversions in Permutations

combinatorics, math

On Changing Tree

data structures, graphs, trees

On Sum of Fractions

math, number theory

On Number of Decompositions into Multipliers

combinatorics, math, number theory

Lightbulb for Minister

geometry

Physical Education and Buns

brute force, implementation, math

Dominoes

constructive algorithms, greedy

Very Beautiful Number

math

Counting Sticks

brute force, implementation

Three matrices

Nineteen

Deleting Substrings

Three Arrays

data structures

Yet Another Number Sequence

combinatorics, math, matrices

Tower of Hanoi

dp

Blocked Points

math

Stock Trading

Stock Trading

greedy

Stock Trading

dp

Three Trees

Three Trees

Supercollider

data structures

Supercollider

brute force

The Tournament

The Tournament

greedy

The Tournament

brute force

Word Folding

brute force

Genetic Engineering

implementation, two pointers

Inna and Large Sweet Matrix

Inna and Sweet Matrix

constructive algorithms

Inna and Candy Boxes

data structures

Inna, Dima and Song

implementation

Inna and Alarm Clock

implementation

Fox and Cross

greedy, implementation

Fox and Number Game

greedy, math

Fox and Meteor Shower

geometry

Fox and Perfect Sets

math

Fox and Card Game

games, greedy, sortings

Fox and Minimal path

bitmasks, constructive algorithms, graphs, implementation, math

Fox and Box Accumulation

greedy, sortings

George and Cards

binary search, data structures

George and Interesting Graph

graph matchings

George and Number

greedy, implementation

George and Round

brute force, greedy, two pointers

George and Sleep

implementation

Game with Points

dp, graphs, implementation, shortest paths

Diverse Substrings

dp, strings, two pointers

Fly, freebies, fly!

binary search, brute force, implementation

Second-Price Auction

implementation

Bear in the Field

math, matrices

Bear and Floodlight

bitmasks, dp, geometry

Bear and Prime Numbers

binary search, brute force, data structures, dp, implementation, math, number theory

Bear and Strings

brute force, greedy, implementation, math, strings

Bear and Raspberry

brute force, greedy, implementation

Multitasking

greedy, implementation, sortings, two pointers

Coder

implementation

Vowels

combinatorics, divide and conquer, dp

Antimatter

dp

Propagating tree

data structures, dfs and similar, trees

Volcanoes

binary search, implementation, sortings, two pointers

Milking cows

data structures, greedy

Ksenia and Combinatorics

combinatorics, dp

Ksenia and Pawns

dfs and similar, graphs, implementation, trees

Arithmetic Progression

implementation, sortings

Number Busters

binary search, math

Ksenia and Pan Scales

greedy, implementation

Sereja and Stairs

greedy, implementation, sortings

Sereja and Dima

greedy, implementation, two pointers

Sereja and Dividing

data structures

Sereja and Cinema

combinatorics, math

Sereja and Brackets

data structures, schedules

Sereja and Tree

graphs, implementation

Sereja and Prefixes

binary search, brute force

New Year Cactus

dp

New Year Tree

data structures, divide and conquer, trees

New Year Tree Decorations

geometry, schedules, sortings

New Year Letter

bitmasks, brute force, dp

New Year Ratings Change

greedy, sortings

New Year Present

constructive algorithms, implementation

New Year Candles

implementation

Semifinals

implementation, sortings

Playing with Dice

brute force

Cookie Clicker

dp, geometry

Developing Game

data structures

Captains Mode

bitmasks, dp, games

Preparing for the Contest

binary search, data structures, greedy, sortings

Maze

dfs and similar

I.O.U.

implementation

Lever

implementation, math

Red and Black Tree

dp, implementation, math