task stringlengths 0 154k | __index_level_0__ int64 0 39.2k |
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The new camp by widely-known over the country Spring Programming Camp is going to start soon. Hence, all the team of friendly curators and teachers started composing the camp's schedule. After some continuous discussion, they came up with a schedule s, which can be represented as a binary string, in which the i-th symb... | 23,600 |
Vasya has recently finished writing a book. Now he faces the problem of giving it the title. Vasya wants the title to be vague and mysterious for his book to be noticeable among others. That's why the title should be represented by a single word containing at least once each of the first k Latin letters and not contain... | 23,601 |
Once Danil the student was returning home from tram stop lately by straight road of length L. The stop is located at the point x = 0, but the Danil's home — at the point x = L. Danil goes from x = 0 to x = L with a constant speed and does not change direction of movement.
There are n street lights at the road, each of... | 23,602 |
Vasya works as a watchman in the gallery. Unfortunately, one of the most expensive paintings was stolen while he was on duty. He doesn't want to be fired, so he has to quickly restore the painting. He remembers some facts about it.
* The painting is a square 3 × 3, each cell contains a single integer from 1 to n, an... | 23,603 |
Frank explained its friend Felman the algorithm of Euclides to calculate the GCD
of two numbers. Then Felman implements it algorithm
int gcd(int a, int b)
{
if (b==0)
return a;
else
return gcd(b,a%b);
}
and it proposes to Frank that makes it
but with a little integer and another integer that has up to 250 d... | 23,604 |
A smelt fishing tournament was held at Lake Hibara. The winner is the one who wins the most smelt.
Create a program that reads the list of participant numbers and the number of fish caught and outputs the number of winners and the number of fish caught. If there are multiple winners, output the one with the lowest par... | 23,605 |
Example
Input
4 5 3
-10 -10
10 -10
10 10
-10 10
1 2
1 3
1 4
2 3
3 4
-20 0
1 0
20 0
Output
No
Yes
No | 23,606 |
You are given an array a_{1}, a_{2}, …, a_{n}. You can remove at most one subsegment from it. The remaining elements should be pairwise distinct.
In other words, at most one time you can choose two integers l and r (1 ≤ l ≤ r ≤ n) and delete integers a_l, a_{l+1}, …, a_r from the array. Remaining elements should be pa... | 23,607 |
The m-floor (m > 1) office of international corporation CodeForces has the advanced elevator control system established. It works as follows.
All office floors are sequentially numbered with integers from 1 to m. At time t = 0, the elevator is on the first floor, the elevator is empty and nobody is waiting for the ele... | 23,608 |
Maze & Items is a puzzle game in which the player tries to reach the goal while collecting items. The maze consists of $W \times H$ grids, and some of them are inaccessible to the player depending on the items he/she has now. The score the player earns is defined according to the order of collecting items. The objectiv... | 23,609 |
In some other world, today is Christmas Eve.
There are N trees planted in Mr. Takaha's garden. The height of the i-th tree (1 \leq i \leq N) is h_i meters.
He decides to choose K trees from these trees and decorate them with electric lights. To make the scenery more beautiful, the heights of the decorated trees shoul... | 23,610 |
As we have seen that Vaishnav was a smart kid and today he has grown up(but he is still childish)
and he is in High school.
Today he was back from school and found that 4 pieces of Pizza was
ordered- one for his father, one for this mother, and one for Vaishnavi and one for him. But
Vaishnav was little late from schoo... | 23,611 |
There is a 120 minute videotape with standard recording. When I set the VCR counter to 00:00:00 with the tape completely rewound and recorded in standard recording mode, I got a certain counter value. Enter this counter value (hours, minutes, seconds), find the length of the remaining tape (recordable time), and create... | 23,612 |
There is an infinitely large triangular grid, as shown below. Each point with integer coordinates contains a lamp.
<image>
Initially, only the lamp at (X, 0) was on, and all other lamps were off. Then, Snuke performed the following operation zero or more times:
* Choose two integers x and y. Toggle (on to off, off t... | 23,613 |
F: Transparent mahjong tiles
You will play mahjong against Mr. Takanosu, a gambler who is rumored to have fallen into the darkness. Mr. Takanosu has been rumored to be a natural disaster, so he has proposed a game using a bizarre mahjong tile called Takanosu tile.
Mahjong is a game in which players hold multiple tile... | 23,614 |
For a non-negative integer K, we define a fractal of level K as follows:
* A fractal of level 0 is a grid with just one white square.
* When K > 0, a fractal of level K is a 3^K \times 3^K grid. If we divide this grid into nine 3^{K-1} \times 3^{K-1} subgrids:
* The central subgrid consists of only black squares.
* Ea... | 23,615 |
Annie has gotten bored of winning every coding contest and farming unlimited rating. Today, she is going to farm potatoes instead.
Annie's garden is an infinite 2D plane. She has n potatoes to plant, and the i-th potato must be planted at (x_i,y_i). Starting at the point (0, 0), Annie begins walking, in one step she c... | 23,616 |
At the foot of Liyushan Mountain, n tents will be carefully arranged to provide accommodation for those who are willing to experience the joy of approaching nature, the tranquility of the night, and the bright starry sky.
The i-th tent is located at the point of (x_i, y_i) and has a weight of w_i. A tent is important ... | 23,617 |
A tree is a graph with n vertices and exactly n - 1 edges; this graph should meet the following condition: there exists exactly one shortest (by number of edges) path between any pair of its vertices.
A subtree of a tree T is a tree with both vertices and edges as subsets of vertices and edges of T.
You're given a tr... | 23,618 |
Chef Al Gorithm was reading a book about climate and oceans when he encountered the word “glaciological”. He thought it was quite curious, because it has the following interesting property: For every two letters in the word, if the first appears x times and the second appears y times, then |x - y| ≤ 1.
Chef Al was happ... | 23,619 |
You are given a boolean function of three variables which is defined by its truth table. You need to find an expression of minimum length that equals to this function. The expression may consist of:
* Operation AND ('&', ASCII code 38)
* Operation OR ('|', ASCII code 124)
* Operation NOT ('!', ASCII code 33) ... | 23,620 |
On the coordinate plane there is a square with sides parallel to the coordinate axes. The length of the square side is equal to a. The lower left corner of the square coincides with the point (0, 0) (the point of the origin). The upper right corner of the square has positive coordinates.
You are given a point with coo... | 23,621 |
Recently Max has got himself into popular CCG "BrainStone". As "BrainStone" is a pretty intellectual game, Max has to solve numerous hard problems during the gameplay. Here is one of them:
Max owns n creatures, i-th of them can be described with two numbers — its health hpi and its damage dmgi. Max also has two types ... | 23,622 |
Valera conducts experiments with algorithms that search for shortest paths. He has recently studied the Floyd's algorithm, so it's time to work with it.
Valera's already written the code that counts the shortest distance between any pair of vertexes in a non-directed connected graph from n vertexes and m edges, contai... | 23,623 |
Rebel spy Heidi has just obtained the plans for the Death Star from the Empire and, now on her way to safety, she is trying to break the encryption of the plans (of course they are encrypted – the Empire may be evil, but it is not stupid!). The encryption has several levels of security, and here is how the first one lo... | 23,624 |
You are given a square matrix consisting of n rows and n columns. We assume that the rows are numbered from 1 to n from top to bottom and the columns are numbered from 1 to n from left to right. Some cells (n - 1 cells in total) of the the matrix are filled with ones, the remaining cells are filled with zeros. We can a... | 23,625 |
This is an interactive problem.
In the Wonderful Metropolis of the Future, there is no need in subway train drivers. Due to the technological progress, they were replaced by the Artificial Intelligence (AI). Unfortunately, one day the predictions of sci-fi writers came true: the AI rebelled and now there is an uncontr... | 23,626 |
Information technologies are developing and are increasingly penetrating into all spheres of human activity. Incredible as it is, the most modern technology are used in farming!
A large farm has a meadow with grazing sheep. Overall there are n sheep and each of them contains a unique number from 1 to n — because the s... | 23,627 |
There were n types of swords in the theater basement which had been used during the plays. Moreover there were exactly x swords of each type. y people have broken into the theater basement and each of them has taken exactly z swords of some single type. Note that different people might have taken different types of swo... | 23,628 |
A penguin Rocher has n sticks. He has exactly one stick with length i for all 1 ≤ i ≤ n.
He can connect some sticks. If he connects two sticks that have lengths a and b, he gets one stick with length a + b. Two sticks, that were used in the operation disappear from his set and the new connected stick appears in his se... | 23,629 |
Bearland has n cities, numbered 1 through n. There are m bidirectional roads. The i-th road connects two distinct cities ai and bi. No two roads connect the same pair of cities. It's possible to get from any city to any other city (using one or more roads).
The distance between cities a and b is defined as the minimum... | 23,630 |
Ivan likes to learn different things about numbers, but he is especially interested in really big numbers. Ivan thinks that a positive integer number x is really big if the difference between x and the sum of its digits (in decimal representation) is not less than s. To prove that these numbers may have different speci... | 23,631 |
Easy and hard versions are actually different problems, so we advise you to read both statements carefully.
You are given a weighted rooted tree, vertex 1 is the root of this tree.
A tree is a connected graph without cycles. A rooted tree has a special vertex called the root. A parent of a vertex v is the last differ... | 23,632 |
Petya loves lucky numbers. Everybody knows that positive integers are lucky if their decimal representation doesn't contain digits other than 4 and 7. For example, numbers 47, 744, 4 are lucky and 5, 17, 467 are not.
One night Petya was sleeping. He was dreaming of being the president of some island country. The count... | 23,633 |
Mashmokh's boss, Bimokh, didn't like Mashmokh. So he fired him. Mashmokh decided to go to university and participate in ACM instead of finding a new job. He wants to become a member of Bamokh's team. In order to join he was given some programming tasks and one week to solve them. Mashmokh is not a very experienced prog... | 23,634 |
Every one is now a days playing games on their smartphones for passing free time. Because of which there are number of game developing companies growing in the market. Not only that, each company is now flooding the market with a lot of games. With such a huge number of games in the market, for each company, with milli... | 23,635 |
Ivan is reading a book about tournaments. He knows that a tournament is an oriented graph with exactly one oriented edge between each pair of vertices. The score of a vertex is the number of edges going outside this vertex.
Yesterday Ivan learned Landau's criterion: there is tournament with scores d1 ≤ d2 ≤ ... ≤ dn ... | 23,636 |
We have a cord whose length is a positive integer. We will perform the following condition until the length of the cord becomes at most 2:
* Operation: Cut the rope at two positions to obtain three cords, each with a length of a positive integer. Among these, discard one with the longest length and one with the shorte... | 23,637 |
Mister B once received a gift: it was a book about aliens, which he started read immediately. This book had c pages.
At first day Mister B read v0 pages, but after that he started to speed up. Every day, starting from the second, he read a pages more than on the previous day (at first day he read v0 pages, at second —... | 23,638 |
We have had record hot temperatures this summer. To avoid heat stroke, you decided to buy a quantity of drinking water at the nearby supermarket. Two types of bottled water, 1 and 0.5 liter, are on sale at respective prices there. You have a definite quantity in your mind, but are willing to buy a quantity larger than ... | 23,639 |
You are given a sequence of positive integers of length N, a = (a_1, a_2, ..., a_N). Your objective is to remove some of the elements in a so that a will be a good sequence.
Here, an sequence b is a good sequence when the following condition holds true:
* For each element x in b, the value x occurs exactly x times in... | 23,640 |
A lottery is being held in a corner of the venue of the Aizu festival. Several types of balls are inside the lottery box and each type has its unique integer printed on the surfaces of the balls. An integer T is printed on the lottery box.
In the lottery, you first declare two integers A and B, and draw up to M balls ... | 23,641 |
Egor likes math, and not so long ago he got the highest degree of recognition in the math community — Egor became a red mathematician. In this regard, Sasha decided to congratulate Egor and give him a math test as a present. This test contains an array a of integers of length n and exactly q queries. Queries were of th... | 23,642 |
You have final scores of an examination for n students. Calculate standard deviation of the scores s1, s2 ... sn.
The variance α2 is defined by
α2 = (∑ni=1(si - m)2)/n
where m is an average of si. The standard deviation of the scores is the square root of their variance.
Constraints
* n ≤ 1000
* 0 ≤ si ≤ 100
Inpu... | 23,643 |
Vasya has a very beautiful country garden that can be represented as an n × m rectangular field divided into n·m squares. One beautiful day Vasya remembered that he needs to pave roads between k important squares that contain buildings. To pave a road, he can cover some squares of his garden with concrete.
For each ga... | 23,644 |
You have a string S consisting of N uppercase English letters. You are allowed to perform at most one operation of following kind: Choose any position in the string, remove the character at that position and insert it back to any other place in the string.
Find the lexicographically smallest string you can achieve.... | 23,645 |
Ralph has a magic field which is divided into n × m blocks. That is to say, there are n rows and m columns on the field. Ralph can put an integer in each block. However, the magic field doesn't always work properly. It works only if the product of integers in each row and each column equals to k, where k is either 1 or... | 23,646 |
Two integer sequences existed initially, one of them was strictly increasing, and another one — strictly decreasing.
Strictly increasing sequence is a sequence of integers [x_1 < x_2 < ... < x_k]. And strictly decreasing sequence is a sequence of integers [y_1 > y_2 > ... > y_l]. Note that the empty sequence and the s... | 23,647 |
There is a plane like Figure 1 with 8 vertical and 8 horizontal squares. There are several bombs on that plane. Figure 2 shows an example (● = bomb).
| □ | □ | □ | □ | □ | □ | □ | □
--- | --- | --- | --- | --- | --- | --- | ---
□ | □ | □ | □ | □ | □ | □ | □
□ | □ | □ | □ | □ | □ | □ | □
□ | □ | □ | □ | □ | □ | □ | □
□... | 23,648 |
A year ago on the bench in public park Leha found an array of n numbers. Leha believes that permutation p is right if for all 1 ≤ i < n condition, that api·api + 1 is not perfect square, holds. Leha wants to find number of right permutations modulo 109 + 7.
Input
First line of input data contains single integer n (1 ... | 23,649 |
Snuke loves flags.
Snuke is placing N flags on a line.
The i-th flag can be placed at either coordinate x_i or coordinate y_i.
Snuke thinks that the flags look nicer when the smallest distance between two of them, d, is larger. Find the maximum possible value of d.
Constraints
* 2 ≤ N ≤ 10^{4}
* 1 ≤ x_i, y_i ≤ 10^... | 23,650 |
Gildong is experimenting with an interesting machine Graph Traveler. In Graph Traveler, there is a directed graph consisting of n vertices numbered from 1 to n. The i-th vertex has m_i outgoing edges that are labeled as e_i[0], e_i[1], …, e_i[m_i-1], each representing the destination vertex of the edge. The graph can h... | 23,651 |
There are N positive integers A_1, A_2, ..., A_N. Takahashi can perform the following operation on these integers any number of times:
* Choose 1 \leq i \leq N and multiply the value of A_i by -2.
Notice that he multiplies it by minus two.
He would like to make A_1 \leq A_2 \leq ... \leq A_N holds. Find the minimu... | 23,652 |
Professor GukiZ has two arrays of integers, a and b. Professor wants to make the sum of the elements in the array a sa as close as possible to the sum of the elements in the array b sb. So he wants to minimize the value v = |sa - sb|.
In one operation professor can swap some element from the array a and some element f... | 23,653 |
Now that Heidi has made sure her Zombie Contamination level checker works, it's time to strike! This time, the zombie lair is a strictly convex polygon on the lattice. Each vertex of the polygon occupies a point on the lattice. For each cell of the lattice, Heidi knows the level of Zombie Contamination – the number of ... | 23,654 |
You are given four integers a, b, x and y. Initially, a ≥ x and b ≥ y. You can do the following operation no more than n times:
* Choose either a or b and decrease it by one. However, as a result of this operation, value of a cannot become less than x, and value of b cannot become less than y.
Your task is to fi... | 23,655 |
There are N children, numbered 1,2,\ldots,N. In the next K days, we will give them some cookies. In the i-th day, we will choose a_i children among the N with equal probability, and give one cookie to each child chosen. (We make these K choices independently.)
Let us define the happiness of the children as c_1 \times ... | 23,656 |
Gaurang has grown up in a mystical universe. He is faced by n consecutive 2D planes. He shoots a particle of decay age k at the planes.
A particle can pass through a plane directly, however, every plane produces an identical copy of the particle going in the opposite direction with a decay age k-1. If a particle has d... | 23,657 |
There are N squares in a row. The leftmost square contains the integer A, and the rightmost contains the integer B. The other squares are empty.
Aohashi would like to fill the empty squares with integers so that the following condition is satisfied:
* For any two adjacent squares, the (absolute) difference of the two... | 23,658 |
A string t is called nice if a string "2017" occurs in t as a subsequence but a string "2016" doesn't occur in t as a subsequence. For example, strings "203434107" and "9220617" are nice, while strings "20016", "1234" and "20167" aren't nice.
The ugliness of a string is the minimum possible number of characters to rem... | 23,659 |
PolandBall is standing in a row with Many Other Balls. More precisely, there are exactly n Balls. Balls are proud of their home land — and they want to prove that it's strong.
The Balls decided to start with selecting exactly m groups of Balls, each consisting either of single Ball or two neighboring Balls. Each Ball ... | 23,660 |
The R2 company has n employees working for it. The work involves constant exchange of ideas, sharing the stories of success and upcoming challenging. For that, R2 uses a famous instant messaging program Spyke.
R2 has m Spyke chats just to discuss all sorts of issues. In each chat, some group of employees exchanges mes... | 23,661 |
A Boolean expression is given. In the expression, each variable appears exactly once. Calculate the number of variable assignments that make the expression evaluate to true.
Input
A data set consists of only one line. The Boolean expression is given by a string which consists of digits, x, (, ), |, &, and ~. Other ... | 23,662 |
Amr is a young coder who likes music a lot. He always wanted to learn how to play music but he was busy coding so he got an idea.
Amr has n instruments, it takes ai days to learn i-th instrument. Being busy, Amr dedicated k days to learn how to play the maximum possible number of instruments.
Amr asked for your help ... | 23,663 |
You are given integers A and B, each between 1 and 3 (inclusive).
Determine if there is an integer C between 1 and 3 (inclusive) such that A \times B \times C is an odd number.
Constraints
* All values in input are integers.
* 1 \leq A, B \leq 3
Input
Input is given from Standard Input in the following format:
A... | 23,664 |
SmallR likes a game called "Deleting Substrings". In the game you are given a sequence of integers w, you can modify the sequence and get points. The only type of modification you can perform is (unexpected, right?) deleting substrings. More formally, you can choose several contiguous elements of w and delete them from... | 23,665 |
Consider the infinite sequence s of positive integers, created by repeating the following steps:
1. Find the lexicographically smallest triple of positive integers (a, b, c) such that
* a ⊕ b ⊕ c = 0, where ⊕ denotes the [bitwise XOR operation](https://en.wikipedia.org/wiki/Bitwise_operation#XOR).
* a, b, ... | 23,666 |
You are given N integers. The i-th integer is a_i. Find the number, modulo 998244353, of ways to paint each of the integers red, green or blue so that the following condition is satisfied:
* Let R, G and B be the sums of the integers painted red, green and blue, respectively. There exists a triangle with positive area... | 23,667 |
The number "zero" is called "love" (or "l'oeuf" to be precise, literally means "egg" in French), for example when denoting the zero score in a game of tennis.
Aki is fond of numbers, especially those with trailing zeros. For example, the number 9200 has two trailing zeros. Aki thinks the more trailing zero digits a n... | 23,668 |
There are N students living in the dormitory of Berland State University. Each of them sometimes wants to use the kitchen, so the head of the dormitory came up with a timetable for kitchen's usage in order to avoid the conflicts:
The first student starts to use the kitchen at the time 0 and should finish the cooking n... | 23,669 |
The weather is fine today and hence it's high time to climb the nearby pine and enjoy the landscape.
The pine's trunk includes several branches, located one above another and numbered from 2 to y. Some of them (more precise, from 2 to p) are occupied by tiny vile grasshoppers which you're at war with. These grasshoppe... | 23,670 |
A palindrome is a string t which reads the same backward as forward (formally, t[i] = t[|t| + 1 - i] for all i ∈ [1, |t|]). Here |t| denotes the length of a string t. For example, the strings 010, 1001 and 0 are palindromes.
You have n binary strings s_1, s_2, ..., s_n (each s_i consists of zeroes and/or ones). You ca... | 23,671 |
Xenia the mathematician has a sequence consisting of n (n is divisible by 3) positive integers, each of them is at most 7. She wants to split the sequence into groups of three so that for each group of three a, b, c the following conditions held:
* a < b < c;
* a divides b, b divides c.
Naturally, Xenia wants... | 23,672 |
Consider a tree (that is, an undirected connected graph without loops) T_1 and a tree T_2. Let's define their cartesian product T_1 × T_2 in a following way.
Let V be the set of vertices in T_1 and U be the set of vertices in T_2.
Then the set of vertices of graph T_1 × T_2 is V × U, that is, a set of ordered pairs o... | 23,673 |
Now that we have recovered all our data, we can return to hacking in to the hacker's system. Our sources tell us that this hacker's lust for power is so great that it is reflected in everything he does, everything he creates. Perhaps this knowledge can become his weakness in our hands, his thirst for power laying a tra... | 23,674 |
Mike has n strings s1, s2, ..., sn each consisting of lowercase English letters. In one move he can choose a string si, erase the first character and append it to the end of the string. For example, if he has the string "coolmike", in one move he can transform it into the string "oolmikec".
Now Mike asks himself: what... | 23,675 |
There are n points marked on the plane. The points are situated in such a way that they form a regular polygon (marked points are its vertices, and they are numbered in counter-clockwise order). You can draw n - 1 segments, each connecting any two marked points, in such a way that all points have to be connected with e... | 23,676 |
Alice: "Hi, Bob! Let's play Nim!"
Bob: "Are you serious? I don't want to play it. I know how to win the game."
Alice: "Right, there is an algorithm to calculate the optimal move using XOR. How about changing the rule so that a player loses a game if he or she makes the XOR to $0$?"
Bob: "It sounds much better now, but ... | 23,677 |
Ikshu and his prime matrix
Ikshu is in love with prime numbers. He has a matrix of size N X N and wants atleast 5 prime numbers in that matrix arranged like a cross as shown in figure. Let us call this matrix "new year matrix"
X X X X X
If matrix is not a "new year matrix" he can alter it with the operation a... | 23,678 |
Polycarp is a head of a circus troupe. There are n — an even number — artists in the troupe. It is known whether the i-th artist can perform as a clown (if yes, then c_i = 1, otherwise c_i = 0), and whether they can perform as an acrobat (if yes, then a_i = 1, otherwise a_i = 0).
Split the artists into two performance... | 23,679 |
You have probably registered on Internet sites many times. And each time you should enter your invented password. Usually the registration form automatically checks the password's crypt resistance. If the user's password isn't complex enough, a message is displayed. Today your task is to implement such an automatic che... | 23,680 |
There is a plane like Figure 1 with 8 vertical and 8 horizontal squares.
□ | □ | □ | □ | □ | □ | □ | □
--- | --- | --- | --- | --- | --- | --- | ---
□ | □ | □ | □ | □ | □ | □ | □
□ | □ | □ | □ | □ | □ | □ | □
□ | □ | □ | □ | □ | □ | □ | □
□ | □ | □ | □ | □ | □ | □ | □
□ | □ | □ | □ | □ | □ | □ | □
□ | □ | □ | □ | □ | □... | 23,681 |
In the year 2xxx, an expedition team landing on a planet found strange objects made by an ancient species living on that planet. They are transparent boxes containing opaque solid spheres (Figure 1). There are also many lithographs which seem to contain positions and radiuses of spheres.
<image>
Figure 1: A strange o... | 23,682 |
Apart from having lots of holidays throughout the year, residents of Berland also have whole lucky years. Year is considered lucky if it has no more than 1 non-zero digit in its number. So years 100, 40000, 5 are lucky and 12, 3001 and 12345 are not.
You are given current year in Berland. Your task is to find how long... | 23,683 |
The Head Chef has received his id from the Association of Byteland . He wants to know the numerical rank of his number among the numbers that can be formed by the exact same digits ( i.e. among numbers having same number of 0's , 1's ... 9's as his id ) . Note that id's can start with 0 . Given a number, find the rank... | 23,684 |
Let n be a positive integer. Let a, b, c be nonnegative integers such that a + b + c = n.
Alice and Bob are gonna play rock-paper-scissors n times. Alice knows the sequences of hands that Bob will play. However, Alice has to play rock a times, paper b times, and scissors c times.
Alice wins if she beats Bob in at lea... | 23,685 |
Alyona decided to go on a diet and went to the forest to get some apples. There she unexpectedly found a magic rooted tree with root in the vertex 1, every vertex and every edge of which has a number written on.
The girl noticed that some of the tree's vertices are sad, so she decided to play with them. Let's call ver... | 23,686 |
Example
Input
4
5
8
58
85
Output
2970.000000000 | 23,687 |
// We decided to drop the legend about the power sockets but feel free to come up with your own :^)
Define a chain:
* a chain of length 1 is a single vertex;
* a chain of length x is a chain of length x-1 with a new vertex connected to the end of it with a single edge.
You are given n chains of lengths l_1,... | 23,688 |
You might have heard about our new goodie distribution program aka the "Laddu Accrual System". This problem is designed to give you a glimpse of its rules. You can read the page once before attempting the problem if you wish, nonetheless we will be providing all the information needed here itself.
Laddu Accrual Syste... | 23,689 |
Vasya has written some permutation p_1, p_2, …, p_n of integers from 1 to n, so for all 1 ≤ i ≤ n it is true that 1 ≤ p_i ≤ n and all p_1, p_2, …, p_n are different. After that he wrote n numbers next_1, next_2, …, next_n. The number next_i is equal to the minimal index i < j ≤ n, such that p_j > p_i. If there is no su... | 23,690 |
Sereja loves integer sequences very much. He especially likes stairs.
Sequence a1, a2, ..., a|a| (|a| is the length of the sequence) is stairs if there is such index i (1 ≤ i ≤ |a|), that the following condition is met:
a1 < a2 < ... < ai - 1 < ai > ai + 1 > ... > a|a| - 1 > a|a|.
For example, sequences [1, 2, 3, 2... | 23,691 |
Nikhil learnt two new commands pwd and cd on the first day of Operating Systems lab.
pwd - command displays the current working directory and,cd - changes the location of working directory.
If the cd parameter contains ".."(without quotes), that means to step one directory back.
The absolute path of directory is separa... | 23,692 |
PolandBall has an undirected simple graph consisting of n vertices. Unfortunately, it has no edges. The graph is very sad because of that. PolandBall wanted to make it happier, adding some red edges. Then, he will add white edges in every remaining place. Therefore, the final graph will be a clique in two colors: white... | 23,693 |
The Committee for Research on Binary Viruses discovered a method of replication for a large family of viruses whose genetic codes are sequences of zeros and ones. Each virus originates from a single gene; for simplicity genes are denoted by integers from 0 to G - 1. At each moment in time a virus is a sequence of genes... | 23,694 |
We have a sandglass consisting of two bulbs, bulb A and bulb B. These bulbs contain some amount of sand. When we put the sandglass, either bulb A or B lies on top of the other and becomes the upper bulb. The other bulb becomes the lower bulb.
The sand drops from the upper bulb to the lower bulb at a rate of 1 gram per... | 23,695 |
There are N balls placed in a row. AtCoDeer the deer is painting each of these in one of the K colors of his paint cans. For aesthetic reasons, any two adjacent balls must be painted in different colors.
Find the number of the possible ways to paint the balls.
Constraints
* 1≦N≦1000
* 2≦K≦1000
* The correct answer i... | 23,696 |
There are n cities and n-1 two-way roads in Treeland. Each road connects a pair of different cities. From any city you can drive to any other, moving only along the roads. Cities are numbered from 1 to n. Yes, of course, you recognized an undirected tree in this description.
The government plans to repair all the road... | 23,697 |
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... | 23,698 |
Link to Russian translation of problem
There are N ants staying at the vertices of the N-regular polygon (one ant at one vertex). At some moment of time all the ants choose one of the edges their vertex is adjacent to and start walking along this edge. If two ants meet at some point of the edge they die. Please find t... | 23,699 |
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