question stringlengths 31 7.12k | source stringclasses 5
values | dataset stringclasses 3
values | index stringlengths 1 5 |
|---|---|---|---|
Dr .: Peter. I did.
Peter: See you again? What kind of silly invention is this time?
Dr .: You invented the detector for that phantom elementary particle axion.
Peter: Speaking of Axion, researchers such as the European Organization for Nuclear Research (CERN) are chasing with a bloody eye, aren't they? Is that true... | aizu | taco | 2013 |
I decided to move and decided to leave this place. There is nothing wrong with this land itself, but there is only one thing to worry about. It's a plum tree planted in the garden. I was looking forward to this plum blooming every year. After leaving here, the fun of spring will be reduced by one. Wouldn't the scent of... | aizu | taco | 23654 |
problem
Given two strings, find the longest of the strings contained in both strings and write a program that answers that length.
Here, the string s included in the string t means that s appears consecutively in t. An empty string, that is, a string of length 0, is included in any string. For example, the string ABR... | aizu | taco | 15770 |
As usual, those who called wolves get together on 8 p.m. at the supermarket. The thing they want is only one, a box lunch that is labeled half price. Scrambling for a few discounted box lunch, they fiercely fight every day. And those who are blessed by hunger and appetite the best can acquire the box lunch, while other... | aizu | taco | 25204 |
Problem
In recent years, turf wars have frequently occurred among squids. It is a recent squid fighting style that multiple squids form a team and fight with their own squid ink as a weapon.
There is still a turf war, and the battlefield is represented by an R × C grid. The squid Gesota, who is participating in the t... | aizu | taco | 3285 |
Peter P. Pepper is facing a difficulty.
After fierce battles with the Principality of Croode, the Aaronbarc Kingdom, for which he serves, had the last laugh in the end. Peter had done great service in the war, and the king decided to give him a big reward. But alas, the mean king gave him a hard question to try his in... | aizu | taco | 14725 |
It was an era when magic still existed as a matter of course. A clan of magicians lived on a square-shaped island created by magic.
At one point, a crisis came to this island. The empire has developed an intercontinental ballistic missile and aimed it at this island. The magic of this world can be classified into eart... | aizu | taco | 15489 |
Example
Input
2 10
Warsaw Petersburg
3
Kiev Moscow Petersburg
150 120
3
Moscow Minsk Warsaw
100 150
Output
380 1 | aizu | taco | 18462 |
Example
Input
2 2
..
..
Output
Second | aizu | taco | 18989 |
problem
There are $ V $ islands, numbered $ 0, 1, ..., V-1 $, respectively. There are $ E $ bridges, numbered $ 0, 1, ..., E-1 $, respectively. The $ i $ th bridge spans island $ s_i $ and island $ t_i $ and is $ c_i $ wide.
The AOR Ika-chan Corps (commonly known as the Squid Corps), which has a base on the island $ ... | aizu | taco | 5776 |
Problem statement
There is a positive integer sequence $ a_1, a_2, \ ldots, a_N $ of length $ N $.
Consider the following game, which uses this sequence and is played by $ 2 $ players on the play and the play.
* Alternately select one of the following operations for the first move and the second move.
* Select a pos... | aizu | taco | 14776 |
Find a cycle in a directed graph G(V, E).
Constraints
* 1 ≤ |V| ≤ 100
* 0 ≤ |E| ≤ 1,000
* si ≠ ti
Input
A directed graph G is given in the following format:
|V| |E|
s0 t0
s1 t1
:
s|E|-1 t|E|-1
|V| is the number of nodes and |E| is the number of edges in the graph. The graph nodes are named with the numbers 0, 1... | aizu | taco | 7597 |
Problem description.
“Murphy’s Law doesn’t meant that something bad will happen. It means that whatever can happen, will happen.”
—Cooper
While traveling across space-time,the data sent by NASA to "The Endurance" spaceship is sent in the format of,
For... | codechef | taco | 23025 |
Chef had a hard day and want to play little bit. The game is called "Chain". Chef has the sequence of symbols. Each symbol is either '-' or '+'. The sequence is called Chain if each two neighboring symbols of sequence are either '-+' or '+-'.
For example sequence '-+-+-+' is a Chain but sequence '-+-+--+' is not.
H... | codechef | code_contests | 834 |
Modern cryptosystems rely heavily on our inability to factor large integers quickly as the basis for their security. They need a quick and easy way to generate and test for primes. Very often, the primes generated are very large numbers. You need to implement ways to test the primality of very large numbers.
Input
Lin... | codechef | taco | 3283 |
Buffalo Marketing
Gopal wants to make some money from buffalos, but in a quite a different way. He decided that his future lay in speculating on buffalos. In the market in his village, buffalos were bought and sold everyday. The price fluctuated over the year, but on any single day the price was always the same.
... | codechef | taco | 15232 |
Mrityunjay is a high-school teacher, currently coaching students for JEE (Joint Entrance Exam). Mrityunjay every year gives prizes to the toppers of JEE in India. A lot of students give this exam in India and it is difficult for him to manually go through results and select two top students from them. So he asked for y... | codechef | taco | 12582 |
You are given n segments on a coordinate line; each endpoint of every segment has integer coordinates. Some segments can degenerate to points. Segments can intersect with each other, be nested in each other or even coincide.
Your task is the following: for every k ∈ [1..n], calculate the number of points with integer ... | codeforces | code_contests | 839 |
Dima the hamster enjoys nibbling different things: cages, sticks, bad problemsetters and even trees!
Recently he found a binary search tree and instinctively nibbled all of its edges, hence messing up the vertices. Dima knows that if Andrew, who has been thoroughly assembling the tree for a long time, comes home and s... | codeforces | code_contests | 840 |
Ivan places knights on infinite chessboard. Initially there are n knights. If there is free cell which is under attack of at least 4 knights then he places new knight in this cell. Ivan repeats this until there are no such free cells. One can prove that this process is finite. One can also prove that position in the en... | codeforces | taco | 928 |
Petya loves lucky numbers. We all know that lucky numbers are the positive integers whose decimal representations contain only the lucky digits 4 and 7. For example, numbers 47, 744, 4 are lucky and 5, 17, 467 are not.
Petya recently learned to determine whether a string of lowercase Latin letters is lucky. For each i... | codeforces | taco | 9187 |
You are given a sequence a_1, a_2, ..., a_n consisting of n non-zero integers (i.e. a_i ≠ 0).
You have to calculate two following values:
1. the number of pairs of indices (l, r) (l ≤ r) such that a_l ⋅ a_{l + 1} ... a_{r - 1} ⋅ a_r is negative;
2. the number of pairs of indices (l, r) (l ≤ r) such that a_l ⋅ a... | codeforces | code_contests | 849 |
There are n students at your university. The programming skill of the i-th student is a_i. As a coach, you want to divide them into teams to prepare them for the upcoming ICPC finals. Just imagine how good this university is if it has 2 ⋅ 10^5 students ready for the finals!
Each team should consist of at least three s... | codeforces | code_contests | 851 |
N ladies attend the ball in the King's palace. Every lady can be described with three values: beauty, intellect and richness. King's Master of Ceremonies knows that ladies are very special creatures. If some lady understands that there is other lady at the ball which is more beautiful, smarter and more rich, she can ju... | codeforces | taco | 4021 |
This is an interactive problem!
Ehab has a hidden permutation p of length n consisting of the elements from 0 to n-1. You, for some reason, want to figure out the permutation. To do that, you can give Ehab 2 different indices i and j, and he'll reply with (p_i|p_j) where | is the [bitwise-or](https://en.wikipedia.org/... | codeforces | taco | 4167 |
Fishing Prince loves trees, and he especially loves trees with only one centroid. The tree is a connected graph without cycles.
A vertex is a centroid of a tree only when you cut this vertex (remove it and remove all edges from this vertex), the size of the largest connected component of the remaining graph is the sma... | codeforces | code_contests | 858 |
Positive integer x is called divisor of positive integer y, if y is divisible by x without remainder. For example, 1 is a divisor of 7 and 3 is not divisor of 8.
We gave you an integer d and asked you to find the smallest positive integer a, such that
* a has at least 4 divisors;
* difference between any two di... | codeforces | code_contests | 861 |
<image>
William is hosting a party for n of his trader friends. They started a discussion on various currencies they trade, but there's an issue: not all of his trader friends like every currency. They like some currencies, but not others.
For each William's friend i it is known whether he likes currency j. There are... | codeforces | taco | 615 |
Sergey attends lessons of the N-ish language. Each lesson he receives a hometask. This time the task is to translate some sentence to the N-ish language. Sentences of the N-ish language can be represented as strings consisting of lowercase Latin letters without spaces or punctuation marks.
Sergey totally forgot about ... | codeforces | taco | 11046 |
The Smart Beaver from ABBYY invented a new message encryption method and now wants to check its performance. Checking it manually is long and tiresome, so he decided to ask the ABBYY Cup contestants for help.
A message is a sequence of n integers a1, a2, ..., an. Encryption uses a key which is a sequence of m integers... | codeforces | taco | 6268 |
You've got an n × n × n cube, split into unit cubes. Your task is to number all unit cubes in this cube with positive integers from 1 to n3 so that:
* each number was used as a cube's number exactly once;
* for each 1 ≤ i < n3, unit cubes with numbers i and i + 1 were neighbouring (that is, shared a side);
* ... | codeforces | taco | 21286 |
The Little Elephant has two permutations a and b of length n, consisting of numbers from 1 to n, inclusive. Let's denote the i-th (1 ≤ i ≤ n) element of the permutation a as ai, the j-th (1 ≤ j ≤ n) element of the permutation b — as bj.
The distance between permutations a and b is the minimum absolute value of the dif... | codeforces | taco | 19121 |
You've got a list of program warning logs. Each record of a log stream is a string in this format: "2012-MM-DD HH:MM:SS:MESSAGE" (without the quotes).
String "MESSAGE" consists of spaces, uppercase and lowercase English letters and characters "!", ".", ",", "?". String "2012-MM-DD" determines a correct date in the y... | codeforces | apps | 2223 |
Emuskald is an avid horticulturist and owns the world's longest greenhouse — it is effectively infinite in length.
Over the years Emuskald has cultivated n plants in his greenhouse, of m different plant species numbered from 1 to m. His greenhouse is very narrow and can be viewed as an infinite line, with each plant o... | codeforces | apps | 3969 |
Shaass has decided to hunt some birds. There are n horizontal electricity wires aligned parallel to each other. Wires are numbered 1 to n from top to bottom. On each wire there are some oskols sitting next to each other. Oskol is the name of a delicious kind of birds in Shaass's territory. Supposed there are ai oskols ... | codeforces | code_contests | 870 |
Iahub does not like background stories, so he'll tell you exactly what this problem asks you for.
You are given a matrix a with n rows and n columns. Initially, all values of the matrix are zeros. Both rows and columns are 1-based, that is rows are numbered 1, 2, ..., n and columns are numbered 1, 2, ..., n. Let's den... | codeforces | taco | 22717 |
Let's call a number k-good if it contains all digits not exceeding k (0, ..., k). You've got a number k and an array a containing n numbers. Find out how many k-good numbers are in a (count each number every time it occurs in array a).
-----Input-----
The first line contains integers n and k (1 ≤ n ≤ 100, 0 ≤ k ≤ 9)... | codeforces | apps | 1392 |
Salve, mi amice.
Et tu quidem de lapis philosophorum. Barba non facit philosophum. Labor omnia vincit. Non potest creatio ex nihilo. Necesse est partibus.
Rp:
I Aqua Fortis
I Aqua Regia
II Amalgama
VII Minium
IV Vitriol
Misce in vitro et æstus, et nil admirari. Festina lente, et nulla tenaci... | codeforces | apps | 4054 |
Have you ever played Pudding Monsters? In this task, a simplified one-dimensional model of this game is used.
<image>
Imagine an infinite checkered stripe, the cells of which are numbered sequentially with integers. Some cells of the strip have monsters, other cells of the strip are empty. All monsters are made of pu... | codeforces | taco | 945 |
Pashmak's homework is a problem about graphs. Although he always tries to do his homework completely, he can't solve this problem. As you know, he's really weak at graph theory; so try to help him in solving the problem.
You are given a weighted directed graph with n vertices and m edges. You need to find a path (perh... | codeforces | code_contests | 877 |
There are many anime that are about "love triangles": Alice loves Bob, and Charlie loves Bob as well, but Alice hates Charlie. You are thinking about an anime which has n characters. The characters are labeled from 1 to n. Every pair of two characters can either mutually love each other or mutually hate each other (the... | codeforces | taco | 21604 |
When Kefa came to the restaurant and sat at a table, the waiter immediately brought him the menu. There were n dishes. Kefa knows that he needs exactly m dishes. But at that, he doesn't want to order the same dish twice to taste as many dishes as possible.
Kefa knows that the i-th dish gives him ai units of satisfact... | codeforces | taco | 24166 |
In Absurdistan, there are n towns (numbered 1 through n) and m bidirectional railways. There is also an absurdly simple road network — for each pair of different towns x and y, there is a bidirectional road between towns x and y if and only if there is no railway between them. Travelling to a different town using one r... | codeforces | taco | 2726 |
Kolya Gerasimov loves kefir very much. He lives in year 1984 and knows all the details of buying this delicious drink. One day, as you probably know, he found himself in year 2084, and buying kefir there is much more complicated.
Kolya is hungry, so he went to the nearest milk shop. In 2084 you may buy kefir in a plas... | codeforces | apps | 169 |
Bear Limak has n colored balls, arranged in one long row. Balls are numbered 1 through n, from left to right. There are n possible colors, also numbered 1 through n. The i-th ball has color ti.
For a fixed interval (set of consecutive elements) of balls we can define a dominant color. It's a color occurring the bigges... | codeforces | taco | 13148 |
Little Alyona is celebrating Happy Birthday! Her mother has an array of n flowers. Each flower has some mood, the mood of i-th flower is a_{i}. The mood can be positive, zero or negative.
Let's define a subarray as a segment of consecutive flowers. The mother suggested some set of subarrays. Alyona wants to choose sev... | codeforces | apps | 554 |
Comrade Dujikov is busy choosing artists for Timofey's birthday and is recieving calls from Taymyr from Ilia-alpinist.
Ilia-alpinist calls every n minutes, i.e. in minutes n, 2n, 3n and so on. Artists come to the comrade every m minutes, i.e. in minutes m, 2m, 3m and so on. The day is z minutes long, i.e. the day cons... | codeforces | apps | 822 |
Berland has a long and glorious history. To increase awareness about it among younger citizens, King of Berland decided to compose an anthem.
Though there are lots and lots of victories in history of Berland, there is the one that stand out the most. King wants to mention it in the anthem as many times as possible.
H... | codeforces | apps | 882 |
Petya is a big fan of mathematics, especially its part related to fractions. Recently he learned that a fraction <image> is called proper iff its numerator is smaller than its denominator (a < b) and that the fraction is called irreducible if its numerator and its denominator are coprime (they do not have positive comm... | codeforces | code_contests | 894 |
Nikita and Sasha play a computer game where you have to breed some magical creatures. Initially, they have k creatures numbered from 1 to k. Creatures have n different characteristics.
Sasha has a spell that allows to create a new creature from two given creatures. Each of its characteristics will be equal to the maxi... | codeforces | taco | 23696 |
Pig is visiting a friend.
Pig's house is located at point 0, and his friend's house is located at point m on an axis.
Pig can use teleports to move along the axis.
To use a teleport, Pig should come to a certain point (where the teleport is located) and choose where to move: for each teleport there is the rightmost ... | codeforces | code_contests | 896 |
Not to be confused with [chessboard](https://en.wikipedia.org/wiki/Chessboard).
<image>
Input
The first line of input contains a single integer N (1 ≤ N ≤ 100) — the number of cheeses you have.
The next N lines describe the cheeses you have. Each line contains two space-separated strings: the name of the cheese and... | codeforces | code_contests | 898 |
A set of points on a plane is called good, if for any two points at least one of the three conditions is true:
* those two points lie on same horizontal line;
* those two points lie on same vertical line;
* the rectangle, with corners in these two points, contains inside or on its borders at least one point of... | codeforces | taco | 21275 |
In a far away kingdom young pages help to set the table for the King. As they are terribly mischievous, one needs to keep an eye on the control whether they have set everything correctly. This time the royal chef Gerasim had the impression that the pages have played a prank again: they had poured the juice from one cup... | codeforces | taco | 16405 |
One fine day, Benny decided to calculate the number of kilometers that she traveled by her bicycle. Therefore, she bought an odometer and installed it onto her bicycle. But the odometer was broken. It was not able to display the digit 3. This would precisely mean, that the odometer won't be able to display the numbers ... | hackerearth | taco | 19919 |
We all know that every positive integer can be represented as the sum of one or more odd integers.
For eg: 4 = 1 + 1 + 1 + 1. Now, your task in this question is to find out the value of G(n), which equals to the number of all possible representations, as described above, of the given integer, n. Since the answer coul... | hackerearth | taco | 818 |
Marut is now a well settled person. Impressed by the coding skills of Marut, N girls wish to marry him. Marut will consider marriage proposals of only those girls who have some special qualities. Qualities are represented by positive non-zero integers.
Marut has a list of M qualities which he wants in a girl. He can a... | hackerearth | taco | 1233 |
Quan_Lank is a great team with some uncommon interests in programming. Sometimes the team loves to solve strings puzzles, sometimes game puzzles and sometimes metrix type puzzles . Yesterday they have added a new interest to their list that is 'number theory' as they have solved some amazing puzzles related to number t... | hackerearth | taco | 18794 |
Raghu and Sayan both like to eat (a lot) but since they are also looking after their health, they can only eat a limited amount of calories per day. So when Kuldeep invites them to a party, both Raghu and Sayan decide to play a game. The game is simple, both Raghu and Sayan will eat the dishes served at the party till ... | hackerearth | taco | 213 |
Shil is now finally in a relationship with Uttu. Both of them like to exchange love letters. However, to avoid exposing their relationship, they use "encryption" to send their messages. They use the famous Caesar cipher to encrypt their messages, which mathematically explained is as follows:
Encryption of a letter x b... | hackerearth | taco | 8940 |
HackerMan has a message that he has coded in form of digits, which means that the message contains only numbers and nothing else. He is fearful that the enemy may get their hands on the secret message and may decode it. HackerMan already knows the message by heart and he can simply destroy it.
But he wants to keep it ... | hackerearth | taco | 11823 |
We have a connected undirected graph with N vertices and M edges. Edge i in this graph (1 \leq i \leq M) connects Vertex U_i and Vertex V_i bidirectionally. We are additionally given N integers D_1, D_2, ..., D_N.
Determine whether the conditions below can be satisfied by assigning a color - white or black - to each v... | atcoder | taco | 534 |
You have a pot and N ingredients. Each ingredient has a real number parameter called value, and the value of the i-th ingredient (1 \leq i \leq N) is v_i.
When you put two ingredients in the pot, they will vanish and result in the formation of a new ingredient. The value of the new ingredient will be (x + y) / 2 where... | atcoder | code_contests | 913 |
There are N mountains ranging from east to west, and an ocean to the west.
At the top of each mountain, there is an inn. You have decided to choose where to stay from these inns.
The height of the i-th mountain from the west is H_i.
You can certainly see the ocean from the inn at the top of the westmost mountain.
F... | atcoder | code_contests | 914 |
Niwango-kun is an employee of Dwango Co., Ltd.
One day, he is asked to generate a thumbnail from a video a user submitted.
To generate a thumbnail, he needs to select a frame of the video according to the following procedure:
* Get an integer N and N integers a_0, a_1, ..., a_{N-1} as inputs. N denotes the number of t... | atcoder | taco | 18764 |
We have an integer sequence A, whose length is N.
Find the number of the non-empty contiguous subsequences of A whose sums are 0. Note that we are counting the ways to take out subsequences. That is, even if the contents of some two subsequences are the same, they are counted individually if they are taken from differ... | atcoder | taco | 9785 |
Snuke lives in another world, where slimes are real creatures and kept by some people. Slimes come in N colors. Those colors are conveniently numbered 1 through N. Snuke currently has no slime. His objective is to have slimes of all the colors together.
Snuke can perform the following two actions:
* Select a color i ... | atcoder | taco | 7698 |
There are a total of n x n squares, n rows vertically and n columns horizontally. Some squares are marked. Create a program that reads the marked state of each square and displays the length of the side of the largest square consisting of only the unmarked squares as an output.
For example, each dataset is given the f... | aizu | taco | 17236 |
Mr. A loves sweets, but recently his wife has told him to go on a diet. One day, when Mr. A went out from his home to the city hall, his wife recommended that he go by bicycle. There, Mr. A reluctantly went out on a bicycle, but Mr. A, who likes sweets, came up with the idea of stopping by a cake shop on the way to e... | aizu | taco | 24004 |
Fibonacci number f(i) appear in a variety of puzzles in nature and math, including packing problems, family trees or Pythagorean triangles. They obey the rule f(i) = f(i - 1) + f(i - 2), where we set f(0) = 1 = f(-1).
Let V and d be two certain positive integers and be N ≡ 1001 a constant. Consider a set of V nodes, e... | aizu | taco | 5605 |
The volume of access to a web service varies from time to time in a day. Also, the hours with the highest volume of access varies from service to service. For example, a service popular in the United States may receive more access in the daytime in the United States, while another service popular in Japan may receive m... | aizu | taco | 8561 |
problem
Cryptography is all the rage at xryuseix's school. Xryuseix, who lives in a grid of cities, has come up with a new cryptography to decide where to meet.
The ciphertext consists of the $ N $ character string $ S $, and the $ S_i $ character determines the direction of movement from the current location. The di... | aizu | taco | 832 |
You have N items that you want to put them into a knapsack. Item i has value vi and weight wi.
You want to find a subset of items to put such that:
* The total value of the items is as large as possible.
* The items have combined weight at most W, that is capacity of the knapsack.
Find the maximum total value of i... | aizu | taco | 2463 |
Find the intersection of two sets $A = \\{a_0, a_1, ..., a_{n-1}\\}$ and $B = \\{b_0, b_1, ..., b_{m-1}\\}$.
Constraints
* $1 \leq n, m \leq 200,000$
* $0 \leq a_0 < a_1 < ... < a_{n-1} \leq 10^9$
* $0 \leq b_0 < b_1 < ... < b_{m-1} \leq 10^9$
Input
The input is given in the following format.
$n$
$a_0 \; a_1 \; .... | aizu | taco | 18107 |
Spring is interesting season of year. Chef is thinking about different things, but last time he thinks about interesting game - "Strange Matrix".
Chef has a matrix that consists of n rows, each contains m elements. Initially, the element aij of matrix equals j. (1 ≤ i ≤ n, 1 ≤ j ≤ m).
Then p times some element aij is... | codechef | apps | 784 |
Chef loves games! But he likes to invent his own. Now he plays game "Digit Jump". Chef has sequence of digits S1, S2,..., SN,. He is staying in the first digit (S1) and want to reach the last digit (SN) in the minimal number of jumps.
While staying in some digit x with index i (digit Si) Chef can jump into digits with... | codechef | code_contests | 940 |
In the hidden country of Lapatrecta, an age old custom was followed to ensure that no outsider ever entered their country undetected. The security measure, though simple, was an effective one. Every person born in Lapatrecta had the initials of all his forefathers included in front of his name. Every once in a while, c... | codechef | taco | 19089 |
NITMAS Fest is live. The members of the community are very busy. People from different colleges have come to compete. But, Naveen is very possessive about his girlfriend, Archana. He always remains close to his girlfriend. Couples (boys in a line and girls in another) have to stand in different rows in a line for a gam... | codechef | taco | 12528 |
p
{
font-size:14px;
text-align:justify;
}
Two positive integers n amd m, n greater than or equal to m, will be given as input.
Make a code that generates all possible combinations of 1,2,3,...,n taking m integers at a time in "increasing order".
Comparison between two combinations:
a1,a2,a3,...,am
b1,b2,b3,...,bm
... | codechef | taco | 14534 |
Codehorses has just hosted the second Codehorses Cup. This year, the same as the previous one, organizers are giving T-shirts for the winners.
The valid sizes of T-shirts are either "M" or from 0 to 3 "X" followed by "S" or "L". For example, sizes "M", "XXS", "L", "XXXL" are valid and "XM", "Z", "XXXXL" are not.
Ther... | codeforces | code_contests | 944 |
During the research on properties of the greatest common divisor (GCD) of a set of numbers, Ildar, a famous mathematician, introduced a brand new concept of the weakened common divisor (WCD) of a list of pairs of integers.
For a given list of pairs of integers (a_1, b_1), (a_2, b_2), ..., (a_n, b_n) their WCD is arbit... | codeforces | code_contests | 945 |
Santa has prepared boxes with presents for n kids, one box for each kid. There are m kinds of presents: balloons, sweets, chocolate bars, toy cars... A child would be disappointed to receive two presents of the same kind, so all kinds of presents in one box are distinct.
Having packed all the presents, Santa realized ... | codeforces | taco | 22709 |
One fine day Sasha went to the park for a walk. In the park, he saw that his favorite bench is occupied, and he had to sit down on the neighboring one. He sat down and began to listen to the silence. Suddenly, he got a question: what if in different parts of the park, the silence sounds in different ways? So it was. Le... | codeforces | taco | 7221 |
You are given a tree (a connected undirected graph without cycles) of n vertices. Each of the n - 1 edges of the tree is colored in either black or red.
You are also given an integer k. Consider sequences of k vertices. Let's call a sequence [a_1, a_2, …, a_k] good if it satisfies the following criterion:
* We will... | codeforces | code_contests | 950 |
The only difference between problems C1 and C2 is that all values in input of problem C1 are distinct (this condition may be false for problem C2).
You are given a sequence a consisting of n integers.
You are making a sequence of moves. During each move you must take either the leftmost element of the sequence or the... | codeforces | code_contests | 951 |
We call a function good if its domain of definition is some set of integers and if in case it's defined in x and x-1, f(x) = f(x-1) + 1 or f(x) = f(x-1).
Tanya has found n good functions f_{1}, …, f_{n}, which are defined on all integers from 0 to 10^{18} and f_i(0) = 0 and f_i(10^{18}) = L for all i from 1 to n. It's... | codeforces | taco | 5741 |
One common way of digitalizing sound is to record sound intensity at particular time moments. For each time moment intensity is recorded as a non-negative integer. Thus we can represent a sound file as an array of n non-negative integers.
If there are exactly K distinct values in the array, then we need k = ⌈ log_{2} ... | codeforces | taco | 23637 |
The new pedestrian zone in Moscow city center consists of n squares connected with each other by n - 1 footpaths. We define a simple path as a sequence of squares such that no square appears in this sequence twice and any two adjacent squares in this sequence are directly connected with a footpath. The size of a simple... | codeforces | taco | 10319 |
Ivan plays an old action game called Heretic. He's stuck on one of the final levels of this game, so he needs some help with killing the monsters.
The main part of the level is a large corridor (so large and narrow that it can be represented as an infinite coordinate line). The corridor is divided into two parts; let'... | codeforces | code_contests | 955 |
There is a river of width n. The left bank of the river is cell 0 and the right bank is cell n + 1 (more formally, the river can be represented as a sequence of n + 2 cells numbered from 0 to n + 1). There are also m wooden platforms on a river, the i-th platform has length c_i (so the i-th platform takes c_i consecuti... | codeforces | code_contests | 956 |
Bob is about to take a hot bath.
There are two taps to fill the bath: a hot water tap and a cold water tap. The cold water's temperature is t1, and the hot water's temperature is t2. The cold water tap can transmit any integer number of water units per second from 0 to x1, inclusive. Similarly, the hot water tap can ... | codeforces | taco | 19397 |
One cold winter evening Alice and her older brother Bob was sitting at home near the fireplace and giving each other interesting problems to solve. When it was Alice's turn, she told the number n to Bob and said:
—Shuffle the digits in this number in order to obtain the smallest possible number without leading zeroes.... | codeforces | taco | 17594 |
You are given two integers a and b, and q queries. The i-th query consists of two numbers l_i and r_i, and the answer to it is the number of integers x such that l_i ≤ x ≤ r_i, and ((x mod a) mod b) ≠ ((x mod b) mod a). Calculate the answer for each query.
Recall that y mod z is the remainder of the division of y by z... | codeforces | code_contests | 960 |
Koa the Koala and her best friend want to play a game.
The game starts with an array a of length n consisting of non-negative integers. Koa and her best friend move in turns and each have initially a score equal to 0. Koa starts.
Let's describe a move in the game:
* During his move, a player chooses any element of... | codeforces | taco | 5493 |
Given a set of integers (it can contain equal elements).
You have to split it into two subsets A and B (both of them can contain equal elements or be empty). You have to maximize the value of mex(A)+mex(B).
Here mex of a set denotes the smallest non-negative integer that doesn't exist in the set. For example:
* m... | codeforces | code_contests | 963 |
You have n distinct points (x_1, y_1),…,(x_n,y_n) on the plane and a non-negative integer parameter k. Each point is a microscopic steel ball and k is the attract power of a ball when it's charged. The attract power is the same for all balls.
In one operation, you can select a ball i to charge it. Once charged, all ba... | codeforces | code_contests | 965 |
Having stayed home alone, Petya decided to watch forbidden films on the Net in secret. "What ungentlemanly behavior!" — you can say that, of course, but don't be too harsh on the kid. In his country films about the Martians and other extraterrestrial civilizations are forbidden. It was very unfair to Petya as he adored... | codeforces | taco | 11608 |
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While trading on his favorite exchange trader William realized that he found a vulnerability. Using this vulnerability he could change the values of certain internal variables to his advantage. To play around he decided to change the values of all internal variables from a_1, a_2, …, a_n to -a_1, -a_2, …, -a_n... | codeforces | code_contests | 968 |
Vasya adores sport programming. He can't write programs but he loves to watch the contests' progress. Vasya even has a favorite coder and Vasya pays special attention to him.
One day Vasya decided to collect the results of all contests where his favorite coder participated and track the progress of his coolness. For e... | codeforces | taco | 3017 |
To celebrate the second ABBYY Cup tournament, the Smart Beaver decided to throw a party. The Beaver has a lot of acquaintances, some of them are friends with each other, and some of them dislike each other. To make party successful, the Smart Beaver wants to invite only those of his friends who are connected by friends... | codeforces | taco | 114 |
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