instruction_seed stringlengths 292 48.7k | found_ngrams listlengths 0 21 |
|---|---|
Your function must accept 2 strings which are correct numbers. It needs to sum them up (without rounding and floating point errors) and return the result (which is also a correct number) without any leading zeros in the integer part, trailing zeros in the decimal part and without minus if the answer is 0 i.e. -0 is not... | [] |
Suppose we have a sequence \$P\$. Every element \$P_n\$ represents the distance between the \$n^{th}\$ prime number and the average of the next two prime numbers.
For example, \$P_1\$ would be the distance between the first prime number (2) and the average of the next two prime numbers (3 and 5), so
\$P_1 = \frac{3+5}{... | [] |
It can be proven that there's exactly one string of infinite length that remain same after base64 encoding Vm0wd2QyUXlVWGxWV0d4V1YwZ...
Given a position, output the character on that position.
Your program would be run on AMD Ryzen 5 5500U@4GHz given 4GB memory and 1 minute (may decrease if RAM turns out to be hard lim... | [] |
Given a base as input, output all pan-digital numbers. A number is pan-digital if it includes every digit in that base at least once, possibly multiple times. Every number is considered to contain an infinite number of leading 0s.
sequence rules apply. Given a base, you may either:
Given an index, output the n-th pan-... | [
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You are given a matrix of size m x n where each cell can contain either 1 or 0. You need to find the largest square submatrix that contains only 1's. The output should be the area of the largest square submatrix.
For example, given the following matrix:
1 0 1 1 1
1 0 1 1 1
1 1 1 1 1
1 0 0 1 0
The largest square submat... | [] |
Your task is to create a program or function, that when given an input list of nonnegative integers of length \$l \ge 2\$ and a nonnegative integer \$c\$ where \$2 \le c \le l\$, group the list into \$c\$ "clusters." What this means is, the average (population) variance* of all the groups should be as low as possible.
... | [] |
Challenge
Given a non-negative integer, find the sum of its digits.
Rules
Your program must take a non-negative integer as input.
Your program should output the sum of the digits of the input integer.
Your program should be able to handle inputs up to 10^100.
Examples
If the input is 123, the output should be 6 (1... | [] |
Description
Given an unsorted array of integers, find the smallest positive integer that does not appear in the array. Your task is to write the shortest code possible to solve this problem.
Input
A non-empty or empty array of integers, where the integers may be negative, zero, or positive.
Output
The smallest positive... | [
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Typically, when we want to represent a magnitude and direction in 2D space, we use a 2-axis vector. These axes are typically called X and Y:
This isn't always convenient, however. The game BattleTech is played on a hexagonal grid, and it's convenient for the axes to line up with the sides of the hexagons. To represent... | [
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Given a permutation, we can define its high-water marks as the indices in which its cumulative maximum increases, or, equivalently, indices with values bigger than all previous values.
For example, the permutation \$ 4, 2, 3, 7, 8, 5, 6, 1 \$, with a cumulative maximum of \$ 4, 4, 4, 7, 8, 8, 8, 8 \$ has \$1, 4, 5\$ as... | [] |
It's easier to put this into coding terminology, so here we go:
First find the average, median, mode, and range.
Then, put those values in another array, then find the new average, median, mode, and range.
Bonus -10 bytes (yeah, negative bytes, because there's already answers) for programs that can handle this many ti... | [
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Take the sequence of all natural numbers in binary, (1, 10, 11, ..) then write them vertically beside each-other like this (least significant bit on top; 0s have been replaced with spaces):
1 1 1 1 1 1 1 1 1
11 11 11 11
1111 1111
11111111
11
Notice there are areas of connected 1s in the... | [] |
Nerdle is a Wordle variant, in which instead of words, the answers are equations. Each equation entered in the game must be a valid one.
Examples: 13³-1=2196, (1/1)²*8=8, (((3)))²=9
The task is to generate and output to a .txt file, one equation per line, all possible 10 character equations that could be an answer for ... | [
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Voronoi diagram is a partition of a plane (or part of plane) into regions close to each of a given set of objects ("seeds").
Here we’ll be dealing with discrete arrays or even rather with ASCII-art:
2 2 4 4 4 4 1 1 1 1 1 1 1 3 3 3 3
2 2 4 4 4 1 1 1 1 1 1 1 3 3 3 3 3
2 2 4 4 4 1 1 1 1 1 1 3 3 3 3 3 3
2 2 2 4 1 1 1 1 1 1... | [] |
This question is an extension of Who's that Polygon? to arbitrary numbers of sides.
A fundamental polygon for a surface is an polygon with a prescribed pairing for all its \$2n\$ sides, each marked with an arrow, such that identifying the sides according to this pairing and the arrow directions produces the surface (up... | [
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This challenge arises from a claim made in a MathOverflow answer and a paper linked in that answer which seems to back up the claim:
Searching for triangular embeddings is much quicker than enumerating over all embeddings… In fact, Jungerman was able to find a triangular embedding of \$K_{18}-K_3\$ in about half an ho... | [] |
This is a sequel to Ragged list pattern matching. In this challenge, the wildcard may match a sequence of items of any length instead of just a single item.
Given a pattern and a ragged list of integers, your task is to decide whether the pattern matches the ragged list.
The pattern is also represented by a ragged list... | [] |
Problem author: https://stats.ioinformatics.org/people/5815
You are given a system with a hidden permutation of the numbers \$1, 2, 3, \ldots, n\$. Your task is to guess this permutation by asking the system a series of questions.
Each question consists of providing the system with a permutation of the numbers \$1, 2, ... | [] |
(Inspired by this challenge.)
Given six real values in three pairs: \$(x_1, x_2), (y_1, y_2),\$ and \$(x_0, y_0)\$, where \$x_1 < x_0 < x_2\$ and \$y_1 < y_0 < y_2\$, create a function which maps between \$(x_1, x_2)\$ and \$(y_1, y_2)\$ which also passes through \$(x_0,y_0)\$. In other words, make some function
$$f: ... | [] |
Non-metals typically* have a fixed number of covalent bonds in every chemical they are part of. Given the number of bonds every element requires, output whether it's possible to construct a single molecule from the given chemicals, such that every atom has it's desired number of bonds.
In other words, output if it's po... | [] |
Given a string s consisting of characters a-z lowercase, generate 5 arrays a1, a2, a3, a4, and a5 of size n (length of s) where the i-th element of each array represents the index of the next occurrence of the i-th character in s, with the following conditions:
If no such occurrence exists, set the value to n (0-based... | [] |
Challenge:
A Frog List is defined by certain rules:
Each frog within a Frog List has an unique positive digit [1-9] as id (any 0 in a list is basically an empty spot, which can mostly be ignored).
A Frog List will always have exactly one Lazy Frog. A Lazy Frog will remain at its position.
Every other frog in a Frog Li... | [] |
You are the sonar captain aboard an underwater submarine. The way sonar works is that every submarine sends out a ping at regular intervals. Each interval is a whole number of seconds. Each submarine has an identifying amplitude, that is no two submarines send out pings at the same amplitude. The amplitude is always a... | [] |
The Greatest Common Divisor, or gcd, of two positive integers \$x\$ and \$y\$ is the largest positive integer that divides both \$x\$ and \$y\$.
The Least Common Multiple, or lcm, of two positive integers \$x\$ and \$y\$ is the smallest positive integer that is a multiple of \$x\$ and \$y\$.
We define the Least Uncommo... | [] |
In this challenge, you're given a list of overlapping waves. Each wave is a finite list with n truthy values, then n falsy values, then n truthy and so on, where n is the wavelength (or half the wavelength I guess, but it really doesn't matter in this challenge). The values of a wave may have an offset, so a wave of wa... | [] |
Related but noticeably different
You are the leader of the guard in the dungeon of an ancient castle.
There are N doors in the dungeon and N guards with keys.
Guard with index i may operates with doors
that have multiple indexes:
i, 2 * i, 3 * i, ...
The way he operates is very dumb: he just toggles state of the door:... | [
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The idea is based on this interactive game. Given a set of eight decimal digits which are not necessarily distinct, your task is to find a hyperjump trip with the specified length.
But what is a hyperjump? I ain't got time to click on HOW TO PLAY
Ok, you have a set of eight digits where none is 0 or 9. Let's say [1, 3,... | [] |
Part I
Previous part was considered encoding of non-empty nested lists with a positive integer.
Reminding the coding procedure \$G(x)\$:
If \$x\$ is a number, \$G(x) = 2^x\$
If \$x\$ is a list \$[n_0, n_1, n_2, n_3, …]\$, \$G(x) = 3^{G(n_0)} \cdot 5^{G(n_1)} \cdot 7^{G(n_2)} \cdot 11^{G(n_3)} \cdot...\$
Bases are cons... | [] |
The problem statement here is pretty simple, take two real numbers on the range [0,1) as input and output their sum, with probability 1.
The catch here is that there are a lot of real numbers. There are in fact so many real numbers that it is impossible to fit all of them into any finite data type. As such, any way to ... | [] |
A Hankel matrix is a square matrix in which each ascending skew-diagonal from left to right is constant, e.g.:
$$\begin{bmatrix} a & b & c & d \\ b & c & d & e \\ c & d & e & f \\ d & e & f & g \end{bmatrix}.$$
Given a sequence of integers \$\{a_n\}\$, we can construct a sequence of Hankel matrices \$\{H_n\}\$, where \... | [] |
Background
Being in a philosophical mood, I remembered one old idea. I think it is suitable for CG.
Duplicates are not found, but it's of course just a kind of totalistic cellular automaton or erosion.
Given an infinite board filled with empty (let 0) cells. We create a figure - a finite set of non-empty (let 1) cells.... | [] |
You may have seen something called a "perpetual dice calendar":
Two 6-sided dice can be rearranged and rotated. One die has the numbers 0, 1, 2, 3, 4, and 5. The second die has the numbers 0, 1, 2, 6, 7, and 8. With this, any day of the month—from 1 to 31—can be displayed on the front of the calendar. The 6 can be rot... | [
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This is my first codegolf post so let me know if I have missed anything. Thanks :)
Description
You are given a list of numbers with 2 < n <= 6 length i.e. [1, 10] or [75, 9, 9, 8, 2, 100]. Given the basic operators + - / * you must try and generate all possible equations. The list of numbers to pull from is: [1, 1, 2, ... | [] |
Euclidean distance between two lattice points \$(x_1, y_1)\$ and \$(x_2, y_2)\$ on a plane is: \$\sqrt{(x_1 - x_2)^2 + (y_1 - y_2)^2}\$.
Imagine now a lattice N x N replicated infinitely many times next to itself. The two points \$(x_1, y_1)\$ and \$(x_2, y_2)\$ also get replicated. Euclidean distance on a torus is t... | [
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320,... |
Although it's done a few times as sub-challenge of a larger challenge, and we also have a challenge to remove the borders of a square matrix, I couldn't find a challenge to output the borders of a given matrix, so here it is.
Challenge:
Given a rectangular-shaped matrix containing integers as input, output its borders.... | [
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[
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18,
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Given a list, L, of sets of numbers like this:
[[1], [0,2,3], [3,1], [1,2,3]]
Output a single list of numbers such that 2 numbers A and B appear next to each other at least once if and only if B in L[A].
That is all such pairs must exist in the output, and only such pairs may exist in the output, where the order of an... | [] |
Carcassonne is a tile-based game, where the objective is to construct Roads, Cities and Monasteries, in order to score points. The game works by players taking turns to draw and place tiles to construct a landscape, then claiming roads, cities and monasteries. An example landscape is:
There are \$19\$ distinct tiles (... | [] |
Background
An interesting way to solve a Sudoku puzzle is to represent it as a Boolean satisfiability problem, and then feed it to a SAT solver.
A Boolean Satisfiability Problem (abbreviated as SAT problem) is a problem in which you are given a set of Boolean expressions, and you need to find a set of values for the va... | [] |
Challenge
Given some JSON data, calculate the maximum depth reached. (Both arrays and dictionaries increase the depth)
Input/Output
The program is expected to read a JSON string from stdin and as soon as the program receives a \n start calculating the max depth, printing it to stdout and terminating the program when do... | [
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Inspired by this SO answer about peak detection.
Background
Persistent homology is a fancy term for a fancy math concept, but in this case all we care about is how it can be used for peak detection. In the case of a 1-dimensional array we can describe the algorithm as follows:
We are given an array as input. We begin b... | [
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Background
You have been given the task of calculating the number of landmines in a field.
You must calculate the landmine score given a list/string of numbers and the landmine number.
The landmine number tells you where landmines are.
For each digit:
if the left digit plus the right digit is equal to the landmine num... | [] |
There is a challenge for multiplying two numbers so I guess this counts too
Given as input a positive real number n compute its natural logarithm.
Your answer should be within \$10^{-6}\$ for \$1 \leq n \leq 10\$ and within \$10^{-3}\$ for \$0.1 \leq n \leq 100\$. You don't need to handle numbers outside this range.
Se... | [] |
Background
You have again x3 been given the task of calculating the number of landmines in a field. But this time, we have no landmine number, and some landmines have exploded.
You must calculate the landmine score given a string of numbers. This is the landscape.
You have no landmine number to start with. Instead, the... | [] |
Conway's Game of Life is a cellular automaton "played" on an infinite grid, filled with cells that are either alive or dead. Once given an initial state, the board evolves indefinitely according to the following rules:
Any live cell with 2 or 3 living neighbours lives to the next state
Any dead cell with exactly 3 liv... | [] |
Diagonalize a vector into a matrix.
Input
A vector, list, array, etc. of integers \$\mathbf{v}\$ of length \$n\$.
Output
A \$n \times n\$ matrix, 2D array, etc. \$A\$ such that for each element \$a_i \in \mathbf{v}\$,
$$
A =
\left( \begin{array}{ccc}
a_1 & 0 & \cdots & 0 \\
0 & a_2 & \cdots & 0 \\
\vdots & \vdots & ... | [] |
Your task is it to output a number as a unary string. You get the number of a non-negative integer input in the range of 0 - 2'000'000'000.
Rules
You can choose any character for the digit you like. But it has to be the same everywhere and for every input.
Output a unary string by outputting this character N times. N... | [] |
Write a function (or a whole program) that outputs (or prints) the following ASCII art:
Output:
1
1 2 1
1 2 3 2 1
1 2 3 4 3 2 1
1 2 3 4 5 4 3 2 1
1 2 3 4 5 6 5 4 3 2 1
1 2 3 4... | [] |
On the Mathematica Stack Exchange, 100xln2 asks:
I need a list of integers […] The list contains integers and is characterized by [three] parameters, lets call them k and j [and listmax], which should be variable.
If k=1 and j=1 then the list would look like this: {1,3,5,7,9,11,....until listmax}
If k=2 and j=3 then t... | [
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The unique-disjointness matrix ( UDISJ(n) ) is a matrix on all pairs of subsets of {1...,n} with entries $$ U_{(A,B)}=\begin{cases}
0, ~ if ~ |A\cap B|=1\\
1, ~ otherwise
\end{cases} $$
Or a bit less mathematical, it is the 2n times 2n matrix with a 0 in all entries where both indices have exactly one common 1 bit in t... | [] |
A powerful number is a positive integer \$n\$ such that for every prime \$p\$ that divides \$n\$, \$p^2\$ also divides \$n\$. Or equivalently, \$n\$ is powerful if and only if it can be written in the form \$n = a^2b^3\$, where \$a\$ and \$b\$ are positive integers.
For example, \$972 = 2^2 \times 3^5\$ is powerful, be... | [] |
This challenge was originally posted on codidact.
At my job we have to sometimes lay out materials. Materials come in large long rolls and are cut into smaller pieces when being laid out.
When we order the rolls we draw up a layout document which describes how we are going to cut them and layout the pieces. This tells... | [] |
Most people would cut circular pizzas into circular sectors to divide them up evenly, but it's also possible to divide them evenly by cutting them vertically like so, where each piece has the same area (assume the pizza has no crust):
Challenge
Your task is to make a program or function that takes a positive integer \... | [] |
Given a sequence of integers with length \$L\$ and an integer \$1 \le N \le L\$, an "\$N\$-rich" permutation is one whose the longest strictly increasing contiguous subsequence has length exactly \$N\$.
For example, let our sequence be [0, 1, 2, 3]. There is exactly one \$1\$-rich permutation, given by [3, 2, 1, 0]. By... | [
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How to play the duck game
This is a 2-player game.
First, we start with a line of blue rubber ducks (represented here as circles):
Now, in each turn, the current player can turn either one blue duck or two adjacent blue ducks red.
So, a valid move would be indexes 2 and 3 (0-indexed):
Then, the other player cou... | [] |
Given a positive integer n, output a number meter formatted like this:
0 1 2 3 4 5 6 7 8 9 0
1 2 3 4 5 6 7 8 9 1 1 1 1 1 1 1 1 1 1 2
The input number is 20 in this example.
More formally, the decimal representations of the numbers are arranged vertically, from most significant digits on the last row ... | [] |
Problem
You are tasked with creating a program that performs emoji encryption on a given string of emojis. In this encryption scheme, each emoji is replaced by a unique character (from a to z). Your program should take an emoji string as input and output the corresponding encrypted string.
The mapping of emojis to char... | [] |
Your task is to find out how often you need to "shuffle" a given list with the following operation until you get back the original list.
start with a list:
(1 2 3 4 5 6 7 8 9)
split it into the elements at odd and even indices
(1 3 5 7 9) (2 4 6 8)
concatenate these two list
(1 3 5 7 9 2 4 6 8)
Input: A list
Output: ... | [] |
Brief description of the game
In the game Otteretto Classic (which you can test directly in your browser; try it!) the player has to form palindromic sequences using adjacent cells on a square grid. Each cell has one of five possible colours, which we will denote by the letters \$\mathrm A, \ldots, \mathrm E\$.
The use... | [] |
Background
Fibonacci numbers are defined as follows:
$$
F_0 = 0, F_1 = 1, F_n = F_{n-1} + F_{n-2}
$$
The Zeckendorf representation is a representation of positive integers as a sum of one or more non-adjacent Fibonacci numbers, using indices 2 and higher. It is known that such a representation is unique for every posit... | [] |
Background
Given an elementary cellular automaton rule number like, for example, 28 = 00011100…
We can swap \$\color{red}{\text{the 2nd bit with the 5th bit}}\$ and \$\color{orange}{\text{the 4th bit with the 7th bit}}\$ to get a rule that acts the same way but mirrored horizontally. This gets us 01000110 = 70.
We ca... | [] |
Alternatively, guess who's doing a course on operating systems
Round Robin scheduling is a way to schedule ready processes in an operating system. Each process in the queue is run for a certain amount of time (quantum), interrupted after that time (if not yet finished), and then added back to the ready queue for anothe... | [
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Description
Given a list of positive integers, write the shortest code to find the number count of the longest consecutive sequence of numbers within the list.
Input
A list of positive integers. You can assume the list is not empty and may contain duplicates.
Output
The length of the longest consecutive sequence of num... | [
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American odds (aka moneyline odds) are numbers like \$+150\$ or \$-400\$ used to express how much a winning bet would pay out. Convert odds to a fair win probability like this:
Positive odds \$+n\$ with \$n \geq 100\$ correspond to $$p=\frac{100}{100+n},$$ producing a probability with \$0 < p \leq 1/2\$.
Negative odds... | [] |
Write a program or function that outputs all positive integers with distinct decimal digits (OEIS: A010784)
Examples:
1 2 3 4 5 6 7 8 9 10 12 13 ...
96 97 98 102 103 ...
123456789 123456798 ... 9876543120 9876543201 9876543210
Rules
You can output the list of numbers in any convenient format (string with separators, ... | [] |
Inspired by this (off topic) post
Given an array of numbers, find the largest sum over a subarray not containing two adjacent elements
[1,2,3,4] -> 6 // [_,2,_,4]
[1,2,3,4,5] -> 9 // [1,_,3,_,5]
[2,2,1,1,2,1,1,2] -> 7 // [2,_,1,_,2,_,_,2]
[3,1,4,1,5,9,2] -> 16 // [3,_,4,_,_,9,_]
[9,8,7,9,9,8] ... | [] |
Background
Numeric Mahjong is a hypothetical variation of Japanese Mahjong, played with nonnegative integers instead of Mahjong tiles. Given a list of nonnegative integers, it is a winning hand if it satisfies the following:
its length is \$3n+2\$ for some nonnegative integer \$n\$, and
it can be partitioned into \$n\... | [] |
Your challenge is to print any 100 consecutive digits of π. You must give the index at which that subsequence appears. The 3 is not included.
For example, you could print any of the following:
1415926535897932384626433832795028841971693993751058209749445923078164062862089986280348253421170679 (index 0)
821480865132823... | [] |
In this challenge, we define a range similarly to Python's range function: A list of positive integers with equal differences between them. For example, [1, 2, 3] is a range from 1 to 3 with a skip count of 1, because there is a difference of 1 between each item, and [4, 7, 10, 13] is a range from 4 to 13 with a skip c... | [] |
In this challenge, we define the complement of a list of positive integers as all positive integers not included in that list. For example, the complement of the even numbers [2, 4, 6, 8...] is the odd numbers [1, 3, 5, 7...]. Your challenge is to, given a monotonically increasing, infinite list of positive integers, ... | [] |
This challenge is to list out all possible words which are built from a pattern of syllables. Words are composed by joining syllables together. Syllables are composed of a number of vowels with some number of consonants optionally to the left and/or right. Your code should take in:
a list of consonants
a list of vowel... | [] |
In this challenge you will take a non-empty (finite) list of (possibly infinite) lists of positive integers, and your task is to output the longest one. An infinite list is longer than a finite list of any length, and any two infinite lists are equally long.
You're guaranteed that there won't be any ties for longest be... | [] |
Given a number \$n\$, you are to compute the sequence of positive numbers where for each number \$a\$, the \$n\$-times multiple \$n\cdot a\$ is missing.
Example
We always start with the sequence of all positive numbers: $$1,2,3,4,5,6,7,8,9,10,11,12,13,14,15, \dots$$
For \$n=2\$, going left-to-right, we first encounter ... | [] |
Not sure if it's correct to ask such a question on this site, but let's try.
Let a(n) be a sequence of positive integer such that a(1) = 1. To reproduce the sequence a(n) through itself, use the following rule: if binary 1xyz is a term then so are 110xyz and 1XYZ where the last one is the same as 1xyz with rewrite 1 ->... | [] |
You work at a beach. In the afternoon, the sun gets quite hot and beachgoers want to be shaded. So you put out umbrellas. When you put out umbrellas you want to shade the entire beach, with as few umbrellas as possible.
Umbrellas come in many sizes. However, larger umbrellas are susceptible to being pulled away by the ... | [] |
Task
Here is an interesting math problem:
Let's say that there are \$n\$ indistinguishable unlabeled objects in a bin. For every "round", pull \$k\$ objects randomly out of the bin with equal probability, and apply a label on each object (Nothing happens to objects already having a label). Then put these \$k\$ objects... | [] |
We already have a challenge for polynomial interpolation: given a list of points, output the coefficients of the polynomial that passes through them.
Hermite interpolation is a generalization of polynomial interpolation. Instead of just specifying the points that the polynomial passes through, we also specify the highe... | [] |
We will think of a partition as a sequence of non-increasing integers.
For a given partition into \$n_1, n_2, \dots, n_k\$ with \$n_1 \geq n_2 \dots n_{k-1} \geq n_k = n\$ we write it out with \$n_i\$ dots on row \$i\$. So for \$6, 1, 1\$ we would write six dots on the first row, one on the second and one on the third... | [] |
Task
Your boss is on another crusade for 'efficiency.' He wants to encourage the use of numbers with fewer syllables, so that they're easier to discuss in meetings. If you want to take some time off work, you're boss would prefer you take 9 days instead of 7. You're boss would prefer a credit card expense of $99,502 ov... | [] |
Imagine there are \$n\$ people \$\{a_1, a_2, \ldots, a_n\}\$ who enter a room in order and sit down in \$n\$ seats, arranged in a row. Each of these people belong to some gang, indicated by an integer \$\{1, 2, \ldots, k\}\$. These gangs hate the members of the other gangs, so they want to sit as far away from those pe... | [
[
16,
11,
220,
17,
11,
220,
18,
11,
220,
19,
11,
220,
20
],
[
11,
220,
17,
11,
220,
18,
11,
220,
19,
11,
220,
20,
11
]
] |
The well-known Urinal Protocol states that each person that takes a urinal will take the one furthest from any other taken urinal. But this fails to account for short urinals; in many cases, a person would prioritize taking a taller urinal in addition to distance.
In the real world, you might struggle to find a restroo... | [] |
The Rudin-Shapiro sequence is a sequence of \$1\$s and \$-1\$s defined as follows: \$r_n = (-1)^{u_n}\$, where \$u_n\$ is the number of occurrences of (possibly overlapping) \$11\$ in the binary representation of \$n\$.
For example, \$r_{461} = -1\$, because \$461\$ in binary is \$111001101\$, which contains \$3\$ occu... | [] |
We need to produce a block cipher round function with a 1 bit round key size and a 7 bit message size with the highest level of cryptographic security according to our measure of security.
Introduction
We are going to need new symmetric encryption functions. We are at the point where we cannot improve the performance o... | [] |
One lane is closed, the vehicles have to thread their way in according to the zip-lock system: One car from one lane, the next car from the other lane, always taking turns.
Input: Two vehicle queues, represented e.g. as strings, in which short cars are represented by individual symbols, lorries by several identical sym... | [] |
It is a well-known fact that you can colour a two-dimensional map with four colours in such a way that two countries with a common border always have different colours. There have already been enough challenges on this topic.
However, the prerequisite for this is that there must be no enclaves, i.e. non-contiguous area... | [] |
Objective
Given two non-negative integers encoded in unbounded-length Gray code, add them and output the result, where the result is also encoded in Gray code.
Gray code
There are many equivalent formulations of Gray code, but here's an intuitive one.
The Gray code encodes each non-negative integer as an infinite bit-s... | [] |
Challenge
This challenge is based on the domino effect:
Initially, each domino is located on one straight line and is in a vertical state. It can be dropped either to the left along the same straight line, or to the right. Then this domino will knock down the next one, and that one, perhaps, the other.
The dominoes are... | [] |
Given a string of ASCII text as input, encode it in BPSK31 using Varicode. You may either output an audio file in any common format, or play the audio over the device speakers. You may output at any sample rate and with any carrier frequency between 500 Hz and 2500 Hz. The sample rate and carrier frequency must be cons... | [] |
You know what a monotonic sequence is: each element is bigger than its predecessor (monotonically rising) or as its successor (monotonically falling).
Bitonic means you have two arms of the sequence, one monotonically rising, the other falling.
For example, 1,3,5,7,6,4,2 is bitonic (rising until 7, then falling until t... | [] |
In this challenge, an infinitely proportional sequence is defined as a infinite sequence of positive integers such that:
All positive integers are contained infinitely many times within the sequence.
As more and more terms are added to the sequence, for all positive integers \$n\$, the ratio of the number of \$n\$s to... | [] |
OEIS sequence A003242 comprises the numbers of Carlitz compositions for any given positive integer. This is the number of integer partitions of the integer for which no two adjacent parts are equal.
For example, for 4:
Generate the possible integer partitions (and their permutations): [1,1,1,1], [1,1,2], [1,2,1], [2,1... | [] |
Given an n non-negative integers, how many numbers must be changed so that each number x appears x times? You cannot add or remove elements, only replace them with other numbers.
For example:
1 6 23 6 9 23 1 1 6
can be turned into:
1 6 2 6 6 2 6 6 6
with 5 changes, which is optimal.
Test cases
0 => 1
1 2 3 => 1
5 5 5... | [] |
Every Brazilian citizen has a national identification number associated with them, named CPF.
This number has 11 digits (formatted as XXX.XXX.XXX-XX) and it's validated by the following (real) algorithm1:
Take the 9 most significant digits of the number. Call it c.
Multiply the n-th least significant digit of c by n+1... | [
[
16,
11,
220,
17,
11,
220,
18,
11,
220,
19,
11,
220,
20
],
[
11,
220,
17,
11,
220,
18,
11,
220,
19,
11,
220,
20,
11
]
] |
I define mousetail's sequence as follows:
If the nth element of the sequence is q, then n+1 must appear q times in the sequence
The sequence is weakly monotonically increasing (i.e. no lower number may follow a higher number)
f(1)=1
I'll show an example of how this works:
the first element is 1
after the 1, come 1 2... | [] |
Historic Tetris Achievement
Blue Scuti became the first ever human to beat the classic game of Tetris on NES.
Here's the Tetris Kill Screen
Challenge
Output the following Tetris Kill Screen board (10x20 blocks)
EEEEEEEEEE
EEEEEEEEEE
EEEEEEEEEE
EEEEEEEEEE
EEEEEEEEEE
EEEEEEEEEE
EEEEEEEEEE
EEEEEEEEEE
EEEEEEEEEE
EEEEGGEEE... | [] |
Earlier I asked about this problem on stackoverflow (link), but now I also want to see the golfiest solutions
Problem:
Given an array of arbitrary numbers, what is the longest subarray that is repeated (appears more than once)? In case there are multiple distinct repeated subarrays that all have the longest length, the... | [
[
16,
11,
220,
17,
11,
220,
18,
11,
220,
19,
11,
220,
20
]
] |
Consider a function \$r\$ where
$$
r(i,k)= \begin{cases}
L_{i+1}-L_i, & \text{if}\ k =0\ \text{ (1st reduction)} \\
r(i,0)-r(\lfloor \log_2{k} \rfloor,k-2^{\lfloor \log_2{k} \rfloor}) & \text{if}\ k \geq 1\ \text{ (2nd reduction)}
\end{cases}
$$
where \$k<2^i\$ and \$L\$ is a finite sequence of integers.
For example,... | [
[
220,
16,
11,
220,
16,
11,
220,
17,
11,
220,
18,
11,
220
],
[
16,
11,
220,
16,
11,
220,
17,
11,
220,
18,
11,
220,
20
]
] |
Definitions
The common methods to generate consecutive composites are
$$\overbrace{(n+1)! + 2, \ (n+1)! + 3, \ \ldots, \ (n+1)! + (n+1)}^{\text{n composites}}$$
$$\overbrace{n!+2,n!+3,...,n!+n}^{\text{n-1 composites}}$$
$$\overbrace{n\#+2,n\#+3,…n\#+n}^{\text{n-1 composites (Primorials)}}$$
A less common method involv... | [] |
Exposition
In this challenge, I am talking about ARM assembly language. ARM is a 32-bit RISC processor; I'll use instruction set up to architecture v6.
To load a constant ("immediate") value into a register, use
the MOV instruction:
MOV r8, #42
To load negative values, use the MVN instruction, with a bit-complement of... | [] |
Even though the concept of phat-fingered-lights-out number should be pretty self-explanatory here is a definition:
Given a nonnegative integer in binary representation a phat-fingered double-bit-flip or phatflip for short replaces a pair of adjacent, equal bits with their complement.
For example given the number 0b1110... | [] |
Input: You are given two numbers n and m.
Create the snail: Given an n >= 3, fill an n * n grid with the numbers from 1 to n * n, starting at the top left, going clockwise to the middle like this (for n = 5):
1 2 3 4 5
16 17 18 19 6
15 24 25 20 7
14 23 22 21 8
13 12 11 10 9
Calculate the sum of the neightbour... | [] |
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