instruction_seed stringlengths 292 48.7k | found_ngrams listlengths 0 21 |
|---|---|
Background
In 1870 Émile Baudot invented Baudot Code, a fixed-length character
encoding for telegraphy. He designed the code to be entered from a
manual keyboard with just five keys; two operated with the left hand and
three with the right:
The right index, middle and ring fingers operate the I, II, and
III keys, res... | [] |
The challenge is to list all ordered partitions (composition (combinatorics)) of a given positive integer n. These are the lists of numbers from 1 to n whose sum is n. For example, given input n = 4, the result should be:
4
1, 3
3, 1
2, 2
2, 1, 1
1, 2, 1
1, 1, 2
1, 1, 1, 1
The result can be in any order... | [] |
Input:
A list/array of integers for which each item is in the range of 2-36.
Output:
The sum of the integers (as base 10), where each next integer is in the base of the previous value (starting with a regular base 10).
Example:
Let's say we have an input like this: [4, 12, 34, 20, 14, 6, 25, 13, 33]
Then we have a sum ... | [
[
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
],
[
220,
16,
11,
220,
17,
11,
220,
18,
11,
220... |
This is sequel to this challenge by Adnan. If you like this challenge, chances are you'll like the other one too. Check it out!
A multiple choice test with 8 questions each with 4 choices might have the answers: BCADBADA. Converted to four different arrays, with true and false if the current letter is the answer, it w... | [] |
Task
Given the pre-order and post-order traversals of a full binary tree, return its in-order traversal.
The traversals will be represented as two lists, both containing n distinct positive integers, each uniquely identifying a node. Your program may take these lists, and output the resulting in-order traversal, using ... | [] |
Credit
My thanks to Rand Al'Thor's letter-based question for the inspiration for this code-golf challenge.
Background
The nature of this challenge is based off the algorithm mentioned by Rand in his "A Triangle Formed of Three Letters":
Start with a sequence of 10 letters each of which is X, Y, or Z.
Under each row, ... | [] |
A guitar fretboard diagram looks like this:
0 1 2 3 4 5 6 7 8 9 10 11 12 <- Fret number (0 means it's open)
|-E--F--F#-G--G#-A--A#-B--C--C#-D--D#-E
|-B--C--C#-D--D#-E--F--F#-G--G#-A--A#-B
|-G--G#-A--A#-B--C--C#-D--D#-E--F--F#-G
|-D--D#-E--F--F#-G--G#-A--A#-B--C--C#-D
|-A--A#-B--C--C#-D--D#-E--F--F#-G--G#-... | [] |
Things to know:
First, lucky numbers.
Lucky numbers are generated like so:
Take all the natural numbers:
1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20...
Then, remove each second number.
1, 3, 5, 7, 9, 11, 13, 15, 17, 19, 21, 23, 25, 27, 29, 31, 33, 35, 37, 39...
Now, 3 is safe.
Remove every 3... | [
[
11,
220,
16,
17,
11,
220,
16,
19,
11,
220,
16,
21,
11
],
[
16,
11,
220,
17,
11,
220,
18,
11,
220,
19,
11,
220,
20
],
[
11,
220,
17,
11,
220,
18,
11,
220,
19,
11,
... |
XKCD #99, with the title "Binary Heart" shows a simple image of ones and zeros, with some digits colored red.
The red heart is visible to the naked eye, but the message hidden in the binary sequence is not. If you remove all the spaces and newlines and interpret the binary sequence as 8 bit ASCII-code, you'll end up ... | [] |
Crash Course on DST
Dempster–Shafer theory (DST) provides a method to combine various sources of evidence to form a belief. Given a list of possible statement (one of which is the true answer), each possible combination of statements is assigned a "mass" indicating the degree of supporting evidence. The total mass of... | [] |
Given a list of indices and zero or more lists of integers, output the lists of integers, sorted in ascending order, with the key priority from the first input.
Example
Let the keys input be [1, 0, 2], and the lists input be [[5, 3, 4], [6, 2, 1], [5, 2, 1]]. Those lists need to be sorted by their second element, then ... | [
[
16,
11,
220,
17,
11,
220,
18,
11,
220,
19,
11,
220,
20
]
] |
Write a program or function that outputs this exact text, case-insensitive:
A, B, C, D, E, F, G,
H, I, J, K, L, M, N, O, P,
Q, R, S,
T, U, V,
W, X, Y, Z.
(Based on the alphabet song that many American kids learn to help memorize the alphabet, though edited for more compressibility.)
The output must look exactly the sa... | [
[
32,
11,
425,
11,
356,
11,
422,
11,
468,
11,
434,
11,
479
]
] |
Challenge
I've recently gotten into 8-bit computers and are fascinated with the workings of them and others alike; thus the objective of this code golf, is to replicate a portion of the Woz Monitor, designed by Steve Wozniak for the Apple I.
You are to store an array of 22 hexadecimal values with a width of two bytes... | [] |
Introduction
A Gray Code is an alternative to binary representation in which a number is incremented by toggling only one bit, rather than a variable amount of bits. Here are some gray codes along with their decimal and binary equivalents:
decimal | binary | gray
-------------------------
0 | 0 | 0
----... | [] |
Introduction
The Atari ST was a rather popular personal computer from the mid 80's to early 90's era, powered by a Motorola 68000 microprocessor. On this machine, the default behavior of the operating system for uncaught CPU exceptions was to display a row of bombs on the screen, as shown in the following picture:
Sou... | [] |
Given a Sudoku puzzle, find all possible marks that can be filled into each empty cell.
Test case
Input:
[
[
// Top left:
[
0, 0, 0,
3, 4, 0,
0, 0, 2
],
// Top middle:
[
7, 4, 0,
0, 0, 0,
0, 0, 3
... | [] |
Given a number determine if it is a folding number.
A folding number is a number such that if you take it binary representation and "fold" it in half, That is take the result of XNOR multiplication of the first half of the number and the second half with it digits in reverse, you will get zero.
If the number has a odd... | [] |
Challenge
Ever seen those movie trailer titles (namely Martian, Interstellar, etc) where they have huge gaps in between letters slowly spreading out?
The challenge is to recreate this effect given a string, gap multiplier and direction, by inserting appropriate amount of spaces in between the letters.
Example
Input: '... | [] |
We have already defined a folding number here.
But now we are going to define a Super Folding Number. A Super Folding number is a number that if folded enough times it will eventually reach one less than a power of two. The method of folding is slightly different than in the folding number question.
The folding algor... | [] |
The Wythoff matrix is an infinite matrix consisting of the Grundy numbers of each square on a chessboard in Wythoff's game.
Each entry in this matrix is equal to the smallest nonnegative number that does not appear anywhere above, to the left, or diagonally northwest of the position of the entry.
The top-left 20-by-20 ... | [] |
String Similarity
String similarity is basically a ratio of how similar one string is to another. This can be calculated in many ways, and there are various algorithms out there for implementing a ratio calculation for string similarity, some being more accurate than others. It's actually very useful to use these metho... | [] |
Introduction
A decimal is terminating if it has a finite number of decimal digits. For example, 0.4 (2/5) is terminating because it has one decimal digit.
A decimal is purely periodic if it has an infinite number of decimal digits and has no decimal digits before its repetent (the part of the decimal that repeats.) For... | [] |
Write a program or function that takes in positive integers a, b and c, and prints or returns a/b to c decimal places, using the operations +-*/% [add, subtract, multiply, divide, modulate] on the positive integers: you can use all that your language allows, but not on floating point numbers. The range of a,b,c would b... | [] |
Backstory
Disclaimer: May contain made up information about kangaroos.
Kangaroos traverse several stages of development. As they grow older and stronger, they can jump higher and longer, and they can jump more times before they get hungry.
In stage 1, the kangaroo is very little and cannot jump at all. Despite this, is... | [] |
Connect Four is a game where two players take turns to drop disks into columns of a vertically mounted grid, and attempt to connect four disks orthogonally or diagonally. When a column is chosen, the disk falls to the lowest empty position in that column, so any game may be completely specified by the size of the grid ... | [] |
Given a number N, draw a left aligned NxN board of numbers, leaving 1 blank (as a space) (I will show diagrams with N=5)
2 3 4 5
6 7 8 9 10
11 12 13 14 15
16 17 18 19 20
21 22 23 24 25
Your job is to construct the Sieve of Eratosthenes, step by step. First, start with 2. It's prime, so leave it there, and re... | [] |
Consider the natural sequence up-to 6 (disregard 1):
2,3,4,5,6
We start scanning from the left (in this case from 2), search for a number divisible by 2 (here 4) and then remove both the numbers from the list (here 2 & 4), such that the list reduces to:
3,5,6
We continue the same process, here leftmost is 3, so we... | [] |
The Goldbach conjecture states that every even number greater than two can be expressed as the sum of two primes. For example,
4 = 2 + 2
6 = 3 + 3
8 = 5 + 3
However, once we get to 10 something interesting happens. Not only can 10 be written as
5 + 5
but it can also be written as
7 + 3
Since 10 can be expressed as t... | [] |
The challenge is to write the fastest code possible for computing the permanent of a matrix.
The permanent of an n-by-n matrix A = (ai,j) is defined as
Here S_n represents the set of all permutations of [1, n].
As an example (from the wiki):
In this question matrices are all square and will only have the values -1 a... | [] |
This challenge was inspired by this Wendy's commercial from 1984.
Illustration by T S Rogers
Your task is to find a hexadecimal 0xBEEF on a binary bun.
The 'beef' consists of the following pattern:
1 0 1 1 (0xB)
1 1 1 0 (0xE)
1 1 1 0 (0xE)
1 1 1 1 (0xF)
And the 'bun' consists of a 12x12 binary matrix, such as:
1 ... | [] |
Introduction
Suppose you have a ruler with numbers from 0 to r-1.
You place an ant between any two of the numbers, and it starts to crawl erratically on the ruler.
The ruler is so narrow that the ant cannot walk from one position to another without walking on all the numbers in between.
As the ant walks on a number for... | [] |
This is different from My Word can beat up your Word as it is less complex and only requires you to calculate it, and not compare them.
To find the digital root, take all of the digits of a number, add them, and repeat until you get a one-digit number. For example, if the number was 12345, you would add 1, 2, 3, 4, and... | [] |
Bailey–Borwein–Plouffe Iterations
We've seen a few pi challenges on PPCG, but none that specifically dictate the algorithm you should be using. I'd like to see implementations of the Bailey–Borwein–Plouffe algorithm in any language up to iteration n. The formula is as follows:
Your algorithm should output each iterati... | [] |
I am interested in seeing programs which don't ask for any input, print a googol copies of some nonempty string, no less, no more, and then stop. A googol is defined as \$10^{100}\$, i.e., 1 followed by a hundred 0's in decimal.
Example output:
111111111111111111111111111111111111111111111111111111111111111111111111...... | [] |
Your challenge is to write a program or function that, when given two strings of equal length, swaps every other character and outputs/returns the resulting strings in either order.
Examples
"Hello," "world!" --> "Hollo!" "werld,"
"code" "golf" --> "codf" "gole"
"happy" "angry" --> "hnpry" "aagpy"
"qwerty" "dvorak" -->... | [] |
Background
Back in the late 90's / first 00's when Flash Web Design was so much cool that noone could live without having a full Flash website, or at least an animated widget, I was hired to develop a "horse races viewer" in Flash/Actionscript, in the shape of an 80's videogame style animation, so the site's visitors c... | [] |
The program should take input the number, the start of the range and the end of the range, and output how many integers the number appears between the start and end of the range, inclusive. Both programs and functions are allowed.
Example Inputs
For example:
//Input example 1
3,1,100
//Input example 2
3
1
100
//Input e... | [] |
This is my first code golf exercise for you:
Your input is two integers n and k. You can assume n >= 1 and k >= 1
You have to output all numbers from 1 to n (inclusively) and replace every element that is a multiple of k or that contains k with "Shaggy".
you can take the input in any convenient form and output it in a ... | [] |
A Primenary (binary-prime) string is one which, when written as a binary grid, every row and column has a prime total.
That's quite a vague explanation, so let's break it down with a worked example...
For this example we'll use the string bunny:
First, find the ASCII code point of each character and its binary repre... | [] |
Inspired by, and in memory of, my dear friend and colleague,
Dan Baronet, 1956 – 2016. R.I.P.
He found the shortest possible APL solution to this task:
Task
Given a Boolean list, count the number of trailing truth values.
Example cases
{} → 0
{0} → 0
{1} → 1
{0, 1, 1, 0, 0} → 0
{1, 1, 1, 0, 1} → 1
{1, 1, 0, 1, 1} → 2
... | [] |
Introduction
In mathematics, a polygonal number is a number represented as dots or pebbles arranged in the shape of a regular polygon. The dots are thought of as alphas (units). These are one type of 2-dimensional figurate numbers.
The number 10, for example, can be arranged as a triangle:
*
**
***
****
But 10 cannot... | [] |
Hearts is a trick-taking card game for 4 players. Each trick is taken by the player who played the highest card of the leading suit. At the end of each hand, the players incur a penalty score depending on the penalty cards they have taken; the task is to determine the scores under Microsoft Hearts rules.
Input
Input is... | [
[
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
]
] |
A monotonic subsequence is a sequence of numbers \$a_1, a_2, ..., a_n\$ such that
$$a_1 \le a_2 \le ... \le a_n \\
\text{or} \\
a_1 \ge a_2 \ge ... \ge a_n$$
[1, 3, 3, 7, 9, 13, 13, 100] is a monotonic (non-decreasing) subsequence, as well as [9, 4, 4, 3, 0, -10, -12] (this one is non-increasing), but [1, 3, 6, 9, 8] i... | [
[
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
]
] |
Problem
The goal is as the title says to find the \$n\$th prime such that \$\text{the prime}-1\$ is divisible by \$n\$.
Explanation
Here is an example so you understand the question, this is not necessarily the way it ought to be solved. It merely as a way to explain the question
given \$3\$ as an input we would first ... | [] |
Let's take a look on a typical loop, which usually performs 8 iterations:
for (int x=0; x<8; ++x);
You have to make it infinite!
It's a popularity-contest for all languages that support such form of for loop. So solution with highest score (upvotes minus downvotes) wins.
If your language has the other form of for loo... | [] |
I love /usr/share/dict/words; it's so handy! I use it for all my programs, whenever I can! You're going to take advantage of this ever so useful file to use, by testing a word's individuality.
Input
A word; defined in this challenge as any string of characters
/usr/share/dict/words in some format; you may hard code i... | [] |
EDITS:
Added link to the plain-text (multiple strings) test data
Added BLANK,EDGE and TIE2 test cases (see Test Data section) (11/25)
Updated the JSON test cases (some lines were ill-formatted) (11/24)
Renju match gone bad ! (well, technically these guys are playing Go, but who cares) Wikisource
TL;DR
Take a 15x15 ... | [] |
Take a non-nested array as input. Turn it into a matrix by using the following method:
Let's say my array is [1, 2, 3, 4, 5]
First, I repeat that array 5 times: (the length)
[[1, 2, 3, 4, 5],
[1, 2, 3, 4, 5],
[1, 2, 3, 4, 5],
[1, 2, 3, 4, 5],
[1, 2, 3, 4, 5]]
Then, I read it along the diagonals:
[[1],
[2, 1],
[3... | [
[
16,
11,
220,
17,
11,
220,
18,
11,
220,
19,
11,
220,
20
]
] |
Task
Given a Boolean matrix, find one (or optionally more) subset(s) of rows which have exactly one True in each column. You may use any algorithm, but must support very large matrices, like the last example.
One possible algorithm (Knuth's Algorithm X)
While there is no requirement to use this algorithm, it may be you... | [
[
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
]
] |
Background
An unlabelled tree may look like this:
o
/ | \
o o o
| / \
o o o
To linearize this tree, we first label each node o with it's number of child nodes:
3
/ | \
1 0 2
| / \
0 0 0
and then write the numbers in a list in a breath-first manner, meaning line by line and left to right:
[3... | [] |
You will write a simple program that prints exactly 1 2 3 4 5 6 7 8 9 10 to STDOUT, Console, or your language's closest output method. No other visible output should be seen. Any other code executed must be back-end only.
This is answer-chaining, so the catch is that you must include the previous answer's source code i... | [] |
Let's use the four basic operations, addition +, multiplication *, subtraction - and division / (float, not integer).
Stewie's sequence is defined as follows:
x = [x(1), x(2)] // Two initial numbers (one indexed)
x(3) = x(1) + x(2)
x(4) = x(2) * x(3)
x(5) = x(3) - x(4)
x(6) = x(4) / x(5)
x(7) = x(5) + x(6)
... and s... | [] |
Introduction
A xenodrome in base n is an integer where all of its digits in base n are different. Here are some OEIS sequences of xenodromes.
For example, in base 16, FACE, 42 and FEDCBA9876543210 are some xenodromes (Which are 64206, 66 and 18364758544493064720 in base 10), but 11 and DEFACED are not.
Challenge
Given ... | [
[
11,
220,
16,
11,
220,
17,
11,
220,
18,
11,
220,
20,
11
],
[
220,
16,
11,
220,
17,
11,
220,
18,
11,
220,
19,
11,
220
]
] |
An unspeakable number is a number which is divisible by seven or has seven as one of its digits. A children game is to count skipping unspeakable numbers
1 2 3 4 5 6 ( ) 8 9 10 11 12 13 ( ) 15 16 ( ) 18 ...
Cantor's version of the game is the sequence defined by recursively filling in the sequence "1 2 3 4 5 6 ( ) 8..... | [] |
Given three sidelengths of a triangle, evaluate its aspect ratio AR given the following formula:
where
The closer to equilaterality a triangle is, the closer to 1 its aspect ratio is. The aspect ratio is bigger or equal to 1 for valid triangles.
Inputs
The input is three real positive numbers which can be encapsulate... | [] |
There’s a famous tricky algorithm for counting the number of set bits in a 32-bit unsigned integer:
int popcount(unsigned x) {
x = (x & 0x55555555) + ((x >> 1) & 0x55555555);
x = (x & 0x33333333) + ((x >> 2) & 0x33333333);
x = (x & 0x0F0F0F0F) + ((x >> 4) & 0x0F0F0F0F);
x = (x & 0x00FF00FF) + ((x >> 8) & 0x... | [] |
Alphabetize Integers
For a given set of numbers, put them in alphabetical order when they are spelled out (i.e. 1: one, 2: two, 90: ninety, 19: nineteen). Your code should work for the range [-999999, 999999]. Output must have a delimiter between numbers. A space will work, as will a space and a comma as shown in the e... | [
[
16,
11,
220,
17,
11,
220,
18,
11,
220,
19,
11,
220,
20
]
] |
Introduction
Consider a sequence of integers and one of its subsequences, say A = [4 2 2 4 4 6 5] and B = [2 4 5].
We want to remove the elements of B from A in order, and there are several ways of doing that:
A = 4 2 2 4 4 6 5
B = 2 4 5
-> 4 2 4 6
A = 4 2 2 4 4 6 5
B = 2 4 5
-> 4 2 4 6
A = ... | [] |
Binary to decimal converter
As far as I can see, we don't have a simple binary to decimal conversion challenge.
Write a program or function that takes a positive binary integer and outputs its decimal value.
You are not allowed to use any builtin base conversion functions. Integer-to-decimal functions (e.g., a functio... | [] |
Introduction and Credit
Imagine you're Amazon. Imagine you have a large number of products for which a lot of people have written reviews scoring 1-5 stars. Now you need to give your customers a summary for each product based on the simple product-scoring association. Because you're Amazon, time is money and as such yo... | [] |
We are putting balls into a fixed number a bins. These bins begin empty.
Empty bin (a=4): 0 0 0 0
And one by one we add balls to the bins.
0 0 0 1 or
0 0 1 0 or
0 1 0 0 or
1 0 0 0
We need a quick way to loop over all the possible states the bins take, without duplicates and without missing any and we don't want t... | [] |
Generate me a QFP chip!
From the sandbox!
QFP is a type of form factor for an electrical component where pins come out the sides of a chip. Here are is a picture of a typical QFP component:
you can see that the general formula is to have 4 sides of equal numbers of pins.
Your challenge is to create a program that tak... | [] |
You're given a non-empty list of positive integers, e.g.
[6 2 9 7 2 6 5 3 3 4]
You should rank these numbers by their value, but as is usual in leaderboards, if there is a tie then all the tied numbers get the same rank, and an appropriate number of ranks is skipped. The expected output for the above list would theref... | [] |
Make a code that takes a list and a number as input, and generates all possible combinations with the length of the number. For example, with the list {0,1} and the number 2:
00
01
10
11
Your program doesn't have to expect characters twice or more often in the list, such as {0,0,0,0,0,1,1,5,5}
Make sure you print the ... | [] |
A secondary number is a positive integer whose prime factors (without multiplicity) are all less than or equal to its square root. 4 is a secondary number, because its only prime factor is 2, which equals its square root. However, 15 is not a secondary number, because it has 5 as a prime factor, which is larger than it... | [
[
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
],
[
220,
16,
11,
220,
17,
11,
220,
18,
11,
220... |
In the decimal representation of every rational number p/q, you have a periodic tail, a non-periodic head, and a section before the decimal point in the following format:
(before decimal point).(non-periodic)(periodic)
Some examples include:
1/70 = 0.0142857... = (0).(0)(142857)
10/7 = 1.428571... = (1).()(428571) ... | [] |
Scenario
One of your friends is struggling on a homework assignment. He needs a simple program which prints the first 404 natural numbers:
1 2 3 4 5 6 7 8 9 10 11 ... 401 402 403 404
Your challenge is simple: write this program for him.
However, your connection is terrible, so 1 random character is lost every time you... | [] |
Introduction
Consider two non-empty integer arrays, say A = [0 3 2 2 8 4] and B = [7 8 7 2].
To perform alignment addition on them, we do the following:
Repeat each array enough times to have total length \$\text{lcm(length(A), length(B))}\$. Here \$\text{lcm}\$ stands for lowest common multiple.
A -> [0 3 2 2 8 4][... | [] |
Help PPCG Claus Deliver his Presents
Overview
PPCG Claus is running hella late delivering his gifts because nowadays we have so many odd little kiddos out there. This makes it much harder for PPCG Claus to get all the presents to the correct place. Your challenge is to help him delvier his presents correctly.
The Compl... | [] |
Prelude:
I wanted to train making test cases, so I'm gonna try them on something easy.
Challenge:
Take any given (string) input (within visible ASCII range) and deduce if it's a number and output something that could be used to evaluate.
Rules:
A number will only contain the characters -0123456789,.
Answers are only r... | [] |
Input:
A non-empty sequence of integers greater than zero, the length of which is greater than 1.
Output:
The largest product of all elements of the longest subsequence between the minimum and maximum elements of sequence including themselves.
Note:
Because the minimum and maximum elements can be repeated, then to a de... | [] |
Positional Awareness
Your task is to generate a program that, for every permutation of its characters (which includes the original program), outputs the positions of every character relative to the original program.
If your program is
Derp
you must output
[0, 1, 2, 3]
(or some equivalent). This is because D is in the... | [] |
The nutty maths professor wants to encode all of their research using a system sure to fox even the wiliest of their competitors!
To this end the professor has decided to change the base of not just the number that they're writing but every single digit in that number, according to which place the digit finds itself in... | [] |
Challenge
Given a non-empty array of integers, e.g.:
[5, 2, 7, 6, 4, 1, 3]
First sever it into arrays where no item is larger than the previous (i.e. non-ascending arrays):
[5, 2] [7, 6, 4, 1] [3]
Next, reverse each array:
[2, 5] [1, 4, 6, 7] [3]
Finally, concatenate them all together:
[2, 5, 1, 4, 6, 7, 3]
This sh... | [
[
16,
11,
220,
17,
11,
220,
18,
11,
220,
19,
11,
220,
20
]
] |
Create a program that prints all whole numbers inclusively between an interval (a, b), and replaces multiples of 8 in the sequence with random (uniformly distributed, independent of other characters), non-numeric, non-whitespace, printable ASCII characters.
Assume 0 < a < b in all cases.
If the number has more than 1 ... | [] |
We had a prime factorization challenge a while ago, but that challenge is nearly six years old and barely meets our current requirements, so I believe it's time for a new one.
Challenge
Write a program or function that takes as input an integer greater than 1 and outputs or returns a list of its prime factors.
Rules
I... | [] |
Given a number n >= 2, output all the positive integers less than n where gcd(n, k) == 1 (with k being any one of the output numbers). Numbers of this sort are coprime to each other.
Example: 10 gives the output [1, 3, 7, 9] (in any form you like, as long as the numbers are unambiguously separated and in some sort of ... | [] |
For any positive 32-bit integer (1 ≤ n ≤ 0xFFFFFFFF) output the number of bits needed to represent that integer.
Test cases
| n | n in binary | bits needed |
|----------------------------------|
| 1 | 1 | 1 |
| 2 | 10 | 2 |
| 3 | 11 | 2 |
| 4 | 10... | [] |
Goal:
Given a hand of 5 cards, determine its value in the game Cribbage.
Input a string through any reasonable means. You can assume the string will always be in this format:
[Card Value][Card Face],[Card Value][Card Face],[Card Value][Card Face],[Card Value][Card Face],[Card Value][Card Face]
Valid Card Values:
A,2,... | [] |
The presents have been opened. The mince-pies have been eaten. The Star Wars have been watched. The Christmas Season is beginning to wind down. By now you may well have pulled a few Christmas Crackers. If you're lucky, instead of the usual useless plastic toys, you may have won a Mystery Calculator with which you ... | [] |
Introduction
Similar to the Fibonacci Sequence, the Padovan Sequence (OEIS A000931) is a sequence of numbers that is produced by adding previous terms in the sequence. The initial values are defined as:
P(0) = P(1) = P(2) = 1
The 0th, 1st, and 2nd terms are all 1. The recurrence relation is stated below:
P(n) = P(n - ... | [
[
11,
220,
17,
11,
220,
18,
11,
220,
19,
11,
220,
20,
11
]
] |
This is the ASCII version of this challenge. The initial post was separated per request by Martin Ender
Introduction
Similar to the Fibonacci Sequence, the Padovan Sequence (OEIS A000931) is a sequence of numbers that is produced by adding previous terms in the sequence. The initial values are defined as:
P(0) = P(1) =... | [
[
11,
220,
17,
11,
220,
18,
11,
220,
19,
11,
220,
20,
11
]
] |
About a year ago on Dec 31, 2015, I had the idea that:
We should make a time capsule string. Everybody gets to add one character and next new years we'll see who can make the best program out of all the characters with the esolangs that exist then.
Doorknob graciously collected characters from the PPCG community and ... | [
[
11,
220,
16,
17,
11,
220,
16,
19,
11,
220,
16,
21,
11
],
[
220,
16,
17,
11,
220,
16,
19,
11,
220,
16,
21,
11,
220
],
[
220,
16,
11,
220,
17,
11,
220,
18,
11,
220,... |
This challenge is simple enough that it's basically all in the title: you're given a positive integer N and you should return the smallest positive integer which is not a divisor of N.
An example: the divisors of N = 24 are 1, 2, 3, 4, 6, 8, 12, 24. The smallest positive integer which is not in that list is 5, so that'... | [
[
220,
16,
11,
220,
17,
11,
220,
18,
11,
220,
19,
11,
220
]
] |
In this challenge, you need to solve 4 different tasks using the same set of characters. You can rearrange the characters, but you can't add or remove characters.
The winner will be the submission that solves all tasks using the smallest number of characters. All tasks must be solved in the same language.
Note that i... | [] |
Challenge
Given a nonempty list of real numbers, compute its median.
Definitions
The median is computed as follows: First sort the list,
if the number of entries is odd, the median is the value in the center of the sorted list,
otherwise the median is the arithmetic mean of the two values closest to the center of the ... | [] |
Given a list of 1s and -1s, determine whether or not it is a valid OVSF code (by outputting a truthy or falsey value).
OVSF codes are defined as follows:
[1] is an OVSF code.
If X is an OVSF code, then X ++ X and X ++ -X are both OVSF codes.
Here ++ is list concatenation, and - negates every element in the list.
No ... | [] |
Balanced bases:
Balanced bases are essentially the same as normal bases, except that digits can be positive or negative, while in normal bases digits can only be positive.
From here on, balanced bases of base b may be represented as balb - so balanced base 4 = bal4.
In this challenge's definition, the range of digits i... | [
[
16,
11,
220,
17,
11,
220,
18,
11,
220,
19,
11,
220,
20
],
[
220,
16,
11,
220,
17,
11,
220,
18,
11,
220,
19,
11,
220
]
] |
This was inspired by part of the 2016 ARML competition Team Problem #6.
Here's the challenge:
You're given a "wildcard sequence", which is a sequence of digits and another character. A string matches this wildcard sequence by the following pseudocode:
w = wildcard
s = string
# s matches w iff
for all 0 >= i > wildcard.... | [
[
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
]
] |
Given 3 input items, a list of coordinate pairs, a 2D string, and a single-character string, output whether the character at each coordinate of the 2D string is equal to the single character. You can take the input in any order and the coordinates may be 1-indexed.
You may take the 2D string as a 2D list, a list of li... | [] |
I think it's easiest to explain this challenge in a sequential manner. Start with an input number \$N\$ and:
Find its highest prime factor
Check numbers above and below \$N\$ and see if the highest prime factor is higher (i.e. the highest prime factor of \$N-1\$ and/or \$N+1\$ is higher than the factor of \$N\$.
Conti... | [] |
I found about Code Golf after writing this program and decided to post the rules here so you can try it out too. I saw this, which is a less restrictive version of my question. I've got a bit more rules which (in my opinion) make the task quite a lot more tougher.
Title says it all. If the input is 8, we should get:
8 ... | [] |
Task
Given a ASCII diagram of a loop
e.g.
....................
......@@@@@.........
......@...@.........
.....@@...@@@@@.....
....@@........@.....
....@........@@.....
....@@@@@@@@@@......
....................
....................
And a location on the loop
e.g.
(7,1)
You must find the inside and outside of the loop
... | [] |
Background
Programmers these days can't seem to keep their buffers straight! A common source of error is trying to use an array index that is too large for the buffer. Your task is to implement a buffer where large indices are reduced to a size that the buffer can handle. Because I decide exactly what's best for everyo... | [
[
16,
11,
220,
17,
11,
220,
18,
11,
220,
19,
11,
220,
20
]
] |
Yup, you read the title right. play the sound of pi.
More specifically, for every digit of pi in the first 1000, map it to a musical note and output the resulting melody to a file.
Basically, each digit turns to a note on the C Major scale (basically the normal scale). so 1 turns to Middle C, 2 turns to D4, 3 turns to ... | [
[
16,
11,
220,
16,
17,
11,
220,
16,
19,
11,
220,
16,
21
]
] |
Challenge
Write a function or program that accepts a line of input, performs a very specific and oddly familiar shuffle on its characters, and outputs the result.
The required shuffling can be described using the following algorithm:
Label each character in the input with a 1 based index.
Write character number 1 as o... | [] |
Given a directed graph, output the longest cycle.
Rules
Any reasonable input format is allowed (e.g. list of edges, connectivity matrix).
The labels are not important, so you may impose any restrictions on the labels that you need and/or desire, so long as they do not contain additional information not given in the in... | [] |
Question :
You will be given the starting and ending integers of a sequence and should return the number of integers within it which do not contain the digit 5. The start and end numbers should be included!
Examples:
1,9 → 1,2,3,4,6,7,8,9 → Result 8
4,17 → 4,6,7,8,9,10,11,12,13,14,16,17 → Result 12
50,60 → 60 → Result... | [] |
Brun's constant is the value to which the sum of the reciprocals of twin prime pairs (1/p and 1/(p+2) where p and p+2 are both prime) converges. It is approximately 1.902160583104.
Given a positive integer N, approximate Brun's constant by summing the reciprocals of the twin prime pairs where both primes in the pair ar... | [] |
(Challenge taken from a multiplayer game (clash of code) at codingame.com)
The challenge
Find the n-th term of the following sequence: 1, 1, 2, 1, 2, 3, 1, 2, 3, 4... or, to make it more obvious, {1}, {1,2}, {1,2,3}, {1,2,3,4}...
The sequence is made up from concatenated ranges from 1 to x, starting from 1, all the way... | [] |
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