instruction_seed stringlengths 292 48.7k | found_ngrams listlengths 0 21 |
|---|---|
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... | [] |
Background
As noted in this question, for all positive integers \$n>2\$ there exists at least one Egyptian fraction representation (EFR) of \$n\$ distinct positive integers \$a_{1} < a_{2} < \dots < a_{n}\$ such that $$ \sum_{k=1}^{n} \frac{1}{a_{k}} = 1. \tag{1} \label{1} $$
When \$n=3\$, for instance, we have $$ \fra... | [] |
A list \$[a_1,a_2,a_3 \cdots a_n]\$ can be uniquely represented as an unordered list of its prefixes - \$ [[a_1],[a_1, a_2], [a_1,a_2,a_3] \cdots [a_1,a_2,a_3 \cdots a_n]] \$. This can be in any order - for example, \$[1, 2, 3]\$ could be represented by any of \$[[1],[1,2],[1,2,3]]\$, \$[[3,2,1],[2,1],[1]]\$, or \$[[2,... | [] |
Challenge
Given ASCII-encoded text input of any size, detect numbers between -1,000,000,000,000,000,000 and 1,000,000,000,000,000,000 exclusive and rewrite them with thousands separators. Use commas only and ignore leading zeroes. Leave the rest of the input unchanged.
Test cases
Input
Output
Description
123
123... | [] |
Given a collection of coloured laces, what would be the probability, \$P\$, that Alice won't create any loops if, until impossible, they tie two uniformly chosen, free lace ends of differing colours together?
For the avoidance of doubt:
Each lace will be of only one colour and will have precisely two ends.
Alice does ... | [] |
I recently found this game and have been enjoying it. Basically, there is a grid of colored tiles and you act by clicking on empty spaces. When you click an empty space, the first tile (if any) in each of the four axis-aligned directions is selected. If any color appears more than once, all tiles of that color are dest... | [] |
Introduction
The game of xiangqi, also known as Chinese chess, is a chess-like game
popular in China, Vietnam, Taiwan, and other East Asian countries. The colours
of the two sides in xiangqi are red and black. There are seven pieces in
xiangqi: the general (G), advisor (A), elephant (E), horse (H), chariot
(R), cannon ... | [] |
Decipher Neurotic Frogs
Now that Puzzling.SE has finally cracked my amphibian-obsessed cipher, let's write a program or function to decrypt it!
(If you want to look at the puzzle before having it spoiled for you, click the above link now.)
How the cipher works
In Neurotic Frogs Ought To Relax In Mud Baths ("Neurotic F... | [] |
Continued fractions are expressions that describe fractions iteratively. They can be represented graphically:
$$
a_0 +\cfrac 1
{a_1 + \cfrac 1
{a_2 + \cfrac 1
{\ddots + \cfrac 1
{a_n}
}
}
}
$$
Or they can be represented as a list of values: \$[a_0 ; a_1, a_2, \dots, a_n]\$
The challenge:
take a base nu... | [
[
64,
62,
16,
11,
264,
62,
17,
11,
1124,
67816,
11,
264,
1089
]
] |
Write a program or function which will provably print all integers exactly once given infinite time and memory.
Possible outputs could be:
0, 1, -1, 2, -2, 3, -3, 4, -4, …
0, 1, 2, 3, 4, 5, 6, 7, 8, 9, -1, -2, -3, -4, -5, -6, -7, -8, -9, 10, 11, …
This is not a valid output, as this would never enumerate negative num... | [
[
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... |
Challenge
Given a number x and a number n, round number x to n significant figures and output the result.
Significant figures
The significant figures of a number are digits that carry meaning contributing to its measurement resolution. This includes all numbers except leading zeroes.
Bear in mind that leading zeroes af... | [] |
This challenge is the first in a two-challenge series about Repetition. The second will be up soon.
In a language called Repetition (something I just made up), there consists an infinite string of 12345678901234567890..., with 1234567890 repeating forever.
The following syntax is available to output numbers:
+-*/: Thi... | [] |
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... | [] |
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