Codeforces

Mar 30, 2025 • Codeforces

112A Petya and Strings

Little Petya loves presents. His mum bought him two strings of the same size for his birthday

May 16, 2025 • Codeforces

Splits

Let's define a split of n as a nonincreasing sequence of positive integers, the sum of which is n

Jul 13, 2025 • Codeforces

Cover Points

There are n points on the plane, (x1,y1),(x2,y2),…,(xn,yn).

May 30, 2025 • Codeforces

Dice Rolling

Mishka got a six-faced dice. It has integer numbers from 2 to 7 written on its faces

Apr 11, 2025 • Codeforces

Anton and Fairy Tale

Anton likes to listen to fairy tales, especially when Danik, Anton's best friend, tells them. Right now Danik tells Anton a fairy tale.

May 03, 2025 • Codeforces

Year of University Entrance

There is the faculty of Computer Science in Berland. In the social net "TheContact.

May 25, 2025 • Codeforces

Maxim Buys an Apartment

Maxim wants to buy an apartment in a new house at Line Avenue of Metropolis.

Jul 22, 2025 • Codeforces

Common Divisors

You are given an array a consisting of n integers.

Aug 24, 2025 • Codeforces

Zmei Gorynich

You are fighting with Zmei Gorynich — a ferocious monster from Slavic myths, a huge dragon-like reptile with multiple heads!

May 02, 2025 • Codeforces

Diagonal Walking

Mikhail walks on a 2D plane. He can go either up or right. You are given a sequence of Mikhail's moves. He thinks that this sequence is too long and he wants.

Aug 22, 2025 • Codeforces

Balanced Tunnel

Consider a tunnel on a one-way road. During a particular day, n cars numbered from 1 to n entered and exited the tunnel exactly once

Mar 29, 2025 • Codeforces

2490. Circular Sentence

A sentence is a list of words that are separated by a single space with no leading or trailing spaces

Apr 03, 2025 • Codeforces

379A New Year Candles

Vasily the Programmer loves romance, so this year he decided to illuminate his room with candles

Aug 14, 2025 • Codeforces

The Artful Expedient

After Karen have found the deterministic winning (losing?) strategy for rock-paper-scissors

Jun 18, 2025 • Codeforces

Definite Game

Chouti was doing a competitive programming competition.

Jun 04, 2025 • Codeforces

Splits

Let's define a split of n as a nonincreasing sequence of positive integers, the sum of which is n

May 29, 2025 • Codeforces

File Name

You can not just take the file and send it. When Polycarp trying to send a file in the social network.

Sep 07, 2025 • Codeforces

Petr and a Combination Lock

Petr has just bought a new car. He's just arrived at the most known Petersburg's petrol station to refuel

Jul 20, 2025 • Codeforces

Yet Another Two Integers Problem

You are given two integers a and b.

Sep 01, 2025 • Codeforces

Add Candies

There are n bags with candies, initially the -th bag contains i candies. You want all the bags to contain an equal amount of candies in the end.

Jul 07, 2025 • Codeforces

Repeating Cipher

Polycarp loves ciphers. He has invented his own cipher called repeating.

Apr 07, 2025 • Codeforces

118A String Task

There are n stones on the table in a row, each of them can be red

Jun 29, 2025 • Codeforces

LCM

Ivan has number b He is sorting through the numbers a from 1

Aug 19, 2025 • Codeforces

World Cup

The last stage of Football World Cup is played using the play-off system.

Aug 02, 2025 • Codeforces

Almost Equal

You are given integer n have to arrange numbers from 1 to 2n using each of them exactly once

Jul 30, 2025 • Codeforces

Buying a TV Set

Monocarp has decided to buy a new TV set and hang it on the wall in his flat.

Apr 12, 2025 • Codeforces

Polycarp and Letters

Polycarp loves lowercase letters and dislikes uppercase ones. Once he got a string s consisting only of lowercase and uppercase Latin letters.

Mar 25, 2025 • Codeforces

Swap Game

Alice and Bob are playing a game on an array a of n positive integers

May 07, 2025 • Codeforces

Bear and Different Names

In the army, it isn't easy to form a group of soldiers that will be effective on the battlefield. The communication is crucial and thus no two soldiers should

May 31, 2025 • Codeforces

Disturbed People

There is a house with n flats situated on the main street of Berlatov.

Jun 25, 2025 • Codeforces

Birthday

Ivan is collecting coins. There are only N different collectible coins, Ivan has K of them

May 19, 2025 • Codeforces

Paper Airplanes

To make a paper airplane, one has to use a rectangular piece of paper. From a sheet of standard size you can make s airplanes.

Jul 06, 2025 • Codeforces

Drinks Choosing

Old timers of Summer Informatics School can remember previous camps in which each student was given a drink of his choice on the vechorka

Aug 23, 2025 • Codeforces

Creating a Character

You play your favourite game yet another time. You chose the character you didn't play before

Aug 25, 2025 • Codeforces

Maximal Continuous Rest

Each day in Berland consists of n hours. Polycarp likes time management. That's why he has a fixed schedule for each day — it is a

Aug 12, 2025 • Codeforces

Mahmoud and Ehab and the wrong algorithm

Maxim wants to buy an apartment in a new house at Line Avenue of Metropolis.

Jul 10, 2025 • Codeforces

Petya and Origami

Petya is having a party soon, and he has decided to invite his n friends.

Aug 03, 2025 • Codeforces

Make Product Equal One

You are given n numbers a1,a2,…,an. With a cost of one coin you can perform the following operation:

May 22, 2025 • Codeforces

Find Amir

A few years ago Sajjad left his school and register to another one due to security reasons. Now he wishes to find Amir, one of his schoolmates and good friends.

Aug 13, 2025 • Codeforces

Points in Segments

You are given a set of n segments on the axis Ox, each segment has integer endpoints between

Jul 05, 2025 • Codeforces

Letters Rearranging

You are given a string s consisting only of lowercase Latin letters.

Jun 19, 2025 • Codeforces

Got Any Grapes

For simplicity, we'll assume that there are only three types of grapes: green grapes, purple grapes and black grapes.

Mar 26, 2025 • Codeforces

1742C -Stripes

On an 8×8 grid, some horizontal rows have been painted red, and some vertical columns have been painted blue

Sep 09, 2025 • Codeforces

Rumor

Vova promised himself that he would never play computer games... But recently Firestorm — a well-known game developing company

Apr 28, 2025 • Codeforces

Equal Sums

You are given k sequences of integers. The length of the i-th sequence equals to ni .

Sep 05, 2025 • Codeforces

From S To T

You are given three strings s, t and p consisting of lowercase Latin letters. You may perform any number (possibly, zero) operations on these strings.

Jun 28, 2025 • Codeforces

Badge

In Summer Informatics School, if a student doesn't behave well, teachers make a hole in his badge. And today one of the teachers caught a group of n students

Aug 10, 2025 • Codeforces

Okabe and Future Gadget Laboratory

Okabe needs to renovate the Future Gadget Laboratory after he tried doing some crazy experiments! The lab is represented as an n by n

May 17, 2025 • Codeforces

Maximize Sum of Digits

Anton has the integer x. He is interested what positive integer, which doesn't exceed x, has the maximum sum of digits.

Jul 31, 2025 • Codeforces

Meme Problem

Try guessing the statement from this picture

Jun 15, 2025 • Codeforces

Chess For Three

Alex, Bob and Carl will soon participate in a team chess tournament.

May 04, 2025 • Codeforces

Commentary Boxes

Berland Football Cup starts really soon! Commentators from all over the world come to the event.

May 11, 2025 • Codeforces

Mister B and Book Reading

Mister B once received a gift: it was a book about aliens, which he started read immediately. This book had c pages.

May 15, 2025 • Codeforces

Hit the Lottery

Allen has a LOT of money. He has n dollars in the bank

Jun 10, 2025 • Codeforces

Cloning Toys

Recently, he found a machine that can clone plush toys

Apr 08, 2025 • Codeforces

Soldier and Bananas

A soldier wants to buy w bananas in the shop. He has to pay k dollars for the first banana.

Apr 23, 2025 • Codeforces

Key races

Two boys decided to compete in text typing on the site "Key races". During the competition, they have to type a text consisting of s characters

Jul 14, 2025 • Codeforces

Sasha and His Trip

Sasha is a very happy guy, that's why he is always on the move. There are n cities in the country where Sasha lives

Jul 22, 2025 • Codeforces

Drinks Choosing

Old timers of Summer Informatics School can remember previous camps in which each student was given a drink

Apr 14, 2025 • Codeforces

Neverending competitions

There are literally dozens of snooker competitions held each year, and team Jinotega

Aug 06, 2025 • Codeforces

Got Any Grapes?

For simplicity, we'll assume that there are only three types of grapes: green grapes, purple grapes and black grapes.

Jun 16, 2025 • Codeforces

Packets

You have n coins, each of the same value of 1.

Jun 27, 2025 • Codeforces

QAQ

QAQ" is a word to denote an expression of crying. Imagine "Q" as eyes with tears and "A" as a mouth.

Jun 08, 2025 • Codeforces

Numbers on the Chessboard

You are given a chessboard of size n×n It is filled with numbers from 1 to n2

Apr 09, 2025 • Codeforces

Petya and Strings

Little Petya loves presents. His mum bought him two strings of the same size for his birthday

Sep 13, 2025 • Codeforces

Mike and palindrome

Mike has a string s consisting of only lowercase English letters. He wants to change exactly one character from the string so that the resulting

Aug 01, 2025 • Codeforces

XORinacci

Cengiz recently learned Fibonacci numbers and now he is studying different algorithms to find them.

Jun 06, 2025 • Codeforces

Heist

There was an electronic store heist last night.

Mar 30, 2025 • Codeforces

427 Prison Transfer

The prison of your city has n prisoners. As the prison can't accommodate all of them, the city mayor has decided to transfer c of the prisoners to a prison.

May 08, 2025 • Codeforces

Fraction

Petya is a big fan of mathematics, especially its part related to fractions.

May 27, 2025 • Codeforces

New Year and the Christmas Ornament

Alice and Bob are decorating a Christmas Tree.

Jul 18, 2025 • Codeforces

Minimum Integer

You are given q queries in the following form:

Apr 24, 2025 • Codeforces

3 Palindrome

In the beginning of the new year Keivan decided to reverse his name. He doesn't like palindromes, so he changed Naviek to Navick.

Sep 06, 2025 • Codeforces

There Are Two Types Of Burgers

There are two types of burgers in your restaurant — hamburgers and chicken burgers! To assemble a hamburger you need two buns and a beef patty.

Jul 25, 2025 • Codeforces

Floor Number

Vasya goes to visit his classmate Petya. Vasya knows that Petya's apartment number is n .

Jun 22, 2025 • Codeforces

The Monster

A monster is chasing after Rick and Morty on another planet. They're so frightened that sometimes they scream

Sep 10, 2025 • Codeforces

DIY Wooden Ladder

Let's denote a k-step ladder as the following structure: exactly k+2 wooden planks, of which

May 05, 2025 • Codeforces

Kuro and Walking Route

Kuro is living in a country called Uberland consisting of n towns, numbered from 1 to n and n−1 bidirectional roads connecting these towns

Jul 17, 2025 • Codeforces

Tokitsukaze and Enhancement

Tokitsukaze is one of the characters in the game "Kantai Collection". In this game, every character has a common attribute

Jun 18, 2025 • Codeforces

Elections

Elections are taking place in Berland. There are n candidates participating in the elections, numbered from 1 to n

Aug 04, 2025 • Codeforces

Cave Painting

Imp is watching a documentary about cave painting.

Apr 26, 2025 • Codeforces

Shell Game

Bomboslav likes to look out of the window in his room and watch lads outside playing famous shell game.

May 14, 2025 • Codeforces

Borya's Diagnosis

It seems that Borya is seriously sick. He is going visit n doctors to find out the exact diagnosis

Apr 06, 2025 • Codeforces

266B Queue at the School

During the break the schoolchildren, boys and girls, formed a queue of n people in the canteen.

Aug 28, 2025 • Codeforces

Choose Two Numbers

There are n boxes with different quantities of candies in each of them. The i-th box has aicandies inside.

Jun 09, 2025 • Codeforces

Between the Offices

As you may know, MemSQL has American offices in both San Francisco and Seattle

Apr 13, 2025 • Codeforces

A Serial Killer

Sherlock is currently trying to catch a serial killer who kills a person each day.

Jul 04, 2025 • Codeforces

Water Buying

Polycarp wants to cook a soup. To do it, he needs to buy exactly n liters of water.

Apr 17, 2025 • Codeforces

Game With Sticks

After winning gold and silver in IOI 2014, Akshat and Malvika want to have some fun. Now they are playing a game on a grid made of n horizontal and m vertical.

Aug 07, 2025 • Codeforces

String Typing

You are given a string s consisting of n lowercase Latin letters. You have to type this string using your keyboard.

May 06, 2025 • Codeforces

Kirill And The Game

Kirill plays a new computer game. He came to the potion store where he can buy any potion. Each potion is characterized by two integers

Apr 16, 2025 • Codeforces

Mahmoud and a Triangle

Mahmoud has n line segments, the i-th of them has length ai. Ehab challenged him to use exactly 3 line segments to form a non-degenerate triangle.

Mar 19, 2025 • Codeforces

Problem - 239A Two Bags of Potatoes

Valera had two bags of potatoes, the first of these bags contains x (x ≥ 1) potatoes.

Jun 01, 2025 • Codeforces

Water Lily

While sailing on a boat, Inessa noticed a beautiful water lily flower above the lake's surface

Mar 18, 2025 • Codeforces

Problem - 231A

One day three best friends Petya, Vasya and Tonya decided to form a team and take part in programming contests.

Jun 14, 2025 • Codeforces

Function Height

The given points are vertices of a plot of a piecewise function. The j-th piece of the function is the segment PjPj+1

Sep 04, 2025 • Codeforces

Most Similar Words

You are given n words of equal length m, consisting of lowercase Latin alphabet letters. The i-th word is denoted si

Jul 02, 2025 • Codeforces

Little C Loves 3 I

Little C loves number «3» very much. He loves all things about it.

Aug 04, 2025 • Codeforces

Convenient For Everybody

In distant future on Earth day lasts for n hours and that's why there are n timezones

May 26, 2025 • Codeforces

Greedy Arkady

k people want to split n candies between them. Each candy should be given to exactly one of them or be thrown away.

Jul 03, 2025 • Codeforces

Frog Jumping

A frog is currently at the point 0 on a coordinate axis Ox It jumps by the following algorithm

Jun 05, 2025 • Codeforces

Wrong Subtraction

Little girl Tanya is learning how to decrease a number by one

Apr 19, 2025 • Codeforces

Jon Snow and his Favourite Number

Jon Snow now has to fight with White Walkers. He has n rangers, each of which has his own strength.

Jul 09, 2025 • Codeforces

Balanced Rating Changes

Another Codeforces Round has just finished! It has gathered n participants, and according to the results

Apr 15, 2025 • Codeforces

Timofey and cubes

Young Timofey has a birthday today! He got kit of n cubes as a birthday present from his parents

Sep 03, 2025 • Codeforces

Remove the Substring (easy version)

The only difference between easy and hard versions is the length of the string.

Aug 29, 2025 • Codeforces

Mislove Has Lost an Array

Mislove had an array a1, a2, ⋯, an of n positive integers, but he has lost it. He only remembers the following facts about it:

Jul 27, 2025 • Codeforces

Three Piles of Candies

Alice and Bob have received three big piles of candies as a gift. Now they want to divide these candies as fair as possible

Jul 16, 2025 • Codeforces

Doors Breaking and Repairing

You are policeman and you are playing a game with Slavik. The game is turn-based and each turn consists of two phases

Aug 30, 2025 • Codeforces

Smallest Word

A has so many colorful magnets on her fridge! Exactly one letter is written on each magnet, 'a' or 'b'. She loves to play with them.

May 20, 2025 • Codeforces

Beautiful Divisors

Recently Luba learned about a special kind of numbers that she calls beautiful numbers.

Jun 21, 2025 • Codeforces

Okabe and Banana Trees

Okabe needs bananas for one of his experiments for some strange reason. So he decides to go to the forest and cut banana trees.

Sep 12, 2025 • Codeforces

Maximal Continuous Rest

Each day in Berland consists of n hours. Polycarp likes time management

Apr 10, 2025 • Codeforces

Taymyr is calling you

Comrade Dujikov is busy choosing artists for Timofey's birthday and is recieving calls from Taymyr from Ilia-alpinist.

Apr 04, 2025 • Codeforces

27A Next Test

«Polygon» is a system which allows to create programming tasks in a simple and professional way.

May 01, 2025 • Codeforces

Fake NP

Tavak and Seyyed are good friends. Seyyed is very funny and he told Tavak to solve the following problem instead of longest-path.

Apr 27, 2025 • Codeforces

Arya and Bran

Bran and his older sister Arya are from the same house. Bran like candies so much, so Arya is going to give him some Candies

Apr 18, 2025 • Codeforces

Timofey and cubes

Young Timofey has a birthday today! He got kit of n cubes as a birthday present from his parents.

Jun 02, 2025 • Codeforces

Pizza, Pizza, Pizza!!!

Katie, Kuro and Shiro are best friends. They have known each other since kindergarten

May 28, 2025 • Codeforces

Polycarp's Pockets

Polycarp has n coins, the value of coin is Polycarp wants to distribute all the coins between his pockets

Jun 03, 2025 • Codeforces

Piles With Stones

There is a beautiful garden of stones in Innopolis.

Mar 17, 2025 • Codeforces

Problem - 158B Taxi

After the lessons n groups of schoolchildren went outside and decided to visit Polycarpus to celebrate his birthday. We know that the i-th group consists

Jul 23, 2025 • Codeforces

Find Divisible

You are given a range of positive integers from l to r

Apr 26, 2025 • Codeforces

Problems in your to-do list

CodeChef recently revamped its practice page to make it easier for users to identify the next problems they should solve by introducing some new features.

Aug 15, 2025 • Codeforces

Mahmoud and Ehab and the message

Mahmoud wants to send a message to his friend Ehab.

Sep 08, 2025 • Codeforces

Block Adventure

Gildong is playing a video game called Block Adventure. In Block Adventure, there are n columns of blocks in a row

May 10, 2025 • Codeforces

If at first you don't succeed

Each student eagerly awaits the day he would pass the exams successfully

Apr 02, 2025 • Codeforces

478A Initial Bet

There are five people playing a game called "Generosity

Jul 15, 2025 • Codeforces

Vitamins

Berland shop sells n kinds of juices. Each juice has its price ci

Jul 21, 2025 • Codeforces

Sport Mafia

Each evening after the dinner the SIS's students gather together to play the game of Sport Mafia.

Jun 07, 2025 • Codeforces

Chips Moving

You are given n chips on a number line. The i-th chip is placed at the integer coordinate

May 21, 2025 • Codeforces

Magic Forest

Imp is in a magic forest, where xorangles grow (wut?)

Sep 02, 2025 • Codeforces

Alphabetic Removals

You are given a string sconsisting of n lowercase Latin letters. Polycarp wants to remove exactly k characters (k≤n) from the string s. Polycarp uses the

May 18, 2025 • Codeforces

Diagonal Walking

Mikhail walks on a 2D plane. He can go either up or right. You are given a sequence of Mikhail's moves. He thinks that this sequence is too long and he wants.

Aug 26, 2025 • Codeforces

Increase and Copy

Initially, you have the array a consisting of one element 1 (a=[1]).

Aug 18, 2025 • Codeforces

Walking Between Houses

There are n houses in a row. They are numbered from 1 to n in order from left to right. Initially you are in the house 1

Jun 23, 2025 • Codeforces

Trailing Loves (or L'oeufs?)

Aki is fond of numbers, especially those with trailing zeros

Jun 26, 2025 • Codeforces

Odds and Ends

Where do odds begin, and where do they end? Where does hope emerge, and will they ever break?

Jul 01, 2025 • Codeforces

Unique Bid Auction

There is a game called "Unique Bid Auction". You can read more about it here

Aug 20, 2025 • Codeforces

BowWow and the Timetable

In the city of Saint Petersburg, a day lasts for 21 minutes. From the main station of Saint Petersburg

Jun 12, 2025 • Codeforces

Love Triangle

As you could know there are no male planes nor female planes. However

Jul 19, 2025 • Codeforces

Equal Candies

There are n boxes with different quantities of candies in each of them. The i-th box has ai candies inside.

Jul 24, 2025 • Codeforces

Lunar New Year and Number Division

Lunar New Year is approaching, and Bob is struggling with his homework – a number division problem.

Apr 01, 2025 • Codeforces

266A Stones on the Table

There are n stones on the table in a row, each of them can be red, green or blue

Aug 05, 2025 • Codeforces

A Prank

JATC and his friend Giraffe are currently in their room, solving some problems.

Apr 05, 2025 • Codeforces

4C Registration system

A new e-mail service "Berlandesk" is going to be opened in Berland in the near future

Jun 13, 2025 • Codeforces

Coins

In Berland, there are two types of coins, having denominations of 2and k burles

May 13, 2025 • Codeforces

Mahmoud and Ehab and the even-odd game

Mahmoud and Ehab play a game called the even-odd game. Ehab chooses his favorite integer n and then they take turns

Jun 11, 2025 • Codeforces

Benches

There are n benches in the Berland Central park. It is known that a people are currently sitting on the bench

Aug 11, 2025 • Codeforces

Array Stabilization

You are given an array a consisting of n integer numbers.

May 12, 2025 • Codeforces

Chess For Three

Three friends gathered to play a few games of chess together

May 24, 2025 • Codeforces

Adjacent Replacements

Mishka got an integer array a of length n as a birthday present (what a surprise!).

Mar 29, 2025 • Codeforces

1734 Select Three Sticks

You are given n sticks with positive integral length a1,a2

Jun 30, 2025 • Codeforces

Pizza, Pizza, Pizza

Katie, Kuro and Shiro are best friends. They have known each other since kindergarten

Aug 09, 2025 • Codeforces

Game Shopping

Maxim wants to buy some games at the local game shop. There are ngames in the shop, the i-th game costs ci

May 23, 2025 • Codeforces

Equator

Polycarp has created his own training plan to prepare for the programming contests. He will train for n days, all days are numbered from 1 to n beginning

Aug 21, 2025 • Codeforces

Code For 1

Jon fought bravely to rescue the wildlings who were attacked by the white-walkers at Hardhome. On his arrival

Aug 08, 2025 • Codeforces

Reach Median

You are given an array a of n integers and an integer s It is guaranteed that n is odd.

Jul 08, 2025 • Codeforces

Fair Game

Petya and Vasya decided to play a game. They have n cards (n is an even number). A single integer is written on each card.

Aug 27, 2025 • Codeforces

Views Matter

You came to the exhibition and one exhibit has drawn your attention. It consists of n stacks of blocks, where the i-th stack consists of ai blocks resting on

Jul 26, 2025 • Codeforces

Snowball

Today's morning was exceptionally snowy. Meshanya decided to go outside and noticed a huge snowball rolling down the mountain.

May 09, 2025 • Codeforces

Hamster Farm

Dima has a hamsters farm. Soon N hamsters will grow up on it and Dima will sell them in a city nearby.