Questions tagged [number]
A competition to solve a particular problem through the usage and manipulation of numbers.
1,300
questions
-1
votes
21
answers
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How Many Paint Tins Do I Need?
Task
Take in 3 inputs. The length of the wall, the height of the wall and the coverage of the paint. Output how many tins of paint are required.
Output
Since there's no way to purchase ...
- 537
4
votes
1
answer
177
views
Convert real numbers between factoradic and positive integer bases
This prompt asked you to convert back and forth to factoradic, but is very limited in scope (only decimal integers from 0 to 10!-1). Your task in this challenge is to reach just a bit further and ...
- 149
13
votes
21
answers
4k
views
German pharmacy payment
Your task is to calculate the amount you have to pay for prescribed medication at a pharmacy in Germany. The amount is simply based on the full price of the item, which will be your input. It is a ...
- 4,896
-1
votes
1
answer
250
views
It's Just Simple Math! [duplicate]
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 ...
- 537
20
votes
23
answers
2k
views
Diagonal Binary Sequence
Challenge:
Given a positive number \$n\$, convert it to binary, and output a sequence where all 1s form a top-left to bottom-right diagonal line, including a ...
- 123k
12
votes
12
answers
748
views
Calculate NDos-size of given integer
Objective
Given a nonnegative integer, calculate its NDos-size as defined below, and output it.
NDos' numeral system
The concept of NDos-size comes from the numeral system I made. It represents every ...
- 5,447
15
votes
11
answers
958
views
Convert a non-negative integer to Barbrack
Barbrack
Your task is to write a program or function that takes a non-negative integer (in decimal or any other convenient base for your language), and output a number in the numbering system Barbrack....
- 305
9
votes
12
answers
3k
views
Funny Numbers :D
The task is to calculate the average "funniness" of a given number given the following scoring system:
1 point for each "420" in it
2 points for each "69" in it
3 points ...
- 115
16
votes
10
answers
1k
views
Find the longest permutations of integers from 1..k such that all neighbouring pairs sum to a square
OEIS A090461 details the ‘numbers k for which there exists a permutation of the numbers 1 to k such that the sum of adjacent numbers is a square’. This has also been the subject of Matt Parker’s ...
- 19k
15
votes
13
answers
2k
views
Keep jumping till a cycle
Objective
You're on a nonempty list of integers that wraps around. You start at the leftmost entry of the list, and keep jumping to the right to the amount of the integer entry you're at.
Eventually, ...
- 5,447
24
votes
23
answers
4k
views
American odds to probabilities
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\$ ...
- 144k
11
votes
20
answers
4k
views
Add two really big numbers
Preamble
We've already proven we're good at adding two numbers, but many solutions only operate on tiny numbers like 2³²-1, honestly we can do a lot better.
The Challenge
Given two unsigned, non-...
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15
votes
13
answers
2k
views
Half even rounding
The round function in Python 3 will round values of the form \$k+\frac{1}{2}\$ (with \$k\$ being an integer) to the nearest even integer, which is apparently better ...
- 5,677
12
votes
18
answers
1k
views
Print a meter of numbers to a specified limit
Given a positive integer n, output a number meter formatted like this:
...
- 169
15
votes
16
answers
833
views
Output the smallest increasing sequence where each term is coprime to preceding 3 terms
This sequence is defined as
Starts with 1, 2, 3
The next element of the sequence is the first number greater than the previous three that is co-prime with each of the previous 3 elements in the ...
- 11.8k
8
votes
8
answers
394
views
Near miss prime multiples
This challenge was originally posted on codidact.
Given a number \$n \geq 3\$ as input output the smallest number \$k\$ such that the modular residues of \$k\$ by the first \$n\$ primes is exactly \$\...
- 96.5k
1
vote
1
answer
158
views
Start a program so that /proc/self/cmdline contains a binary representation of the input number
I am sorry for the very long description. But i think some information of how /proc/self/cmdline works and how it can be used to get a integer input was necessary.
...
10
votes
13
answers
1k
views
Landmine Number IV
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 ...
- 1,777
14
votes
19
answers
3k
views
Vanilla Natural Logarithm Challenge
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 ...
- 11.8k
10
votes
13
answers
2k
views
Landmine Number II
Background
You have again been given the task of calculating the number of landmines in a field. However, we have now travelled into the flatlands.
You must calculate the landmine score given a list/...
- 1,777
13
votes
27
answers
2k
views
Landmine Number I
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 ...
- 1,777
21
votes
32
answers
2k
views
Reversed Squares
Given an integer n, your task is to determine whether it is a perfect square that when reversed, is still a perfect square. You may assume n is always positive.
When numbers such as 100 (10x10) are ...
- 3,443
6
votes
6
answers
724
views
Detect Maxima Using Persistent Homology
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. ...
- 3,977
47
votes
38
answers
3k
views
Last odd digit of power of 2
Task
Given \$n\$, output position of the last odd digit in the decimal representation of \$2^n\$ (counting from the end).
Rules
There are no odd digits for \$n=1,2,3,6,11\$ \$(2, 4, 8, 64, 2048)\$ - ...
- 15.1k
15
votes
6
answers
1k
views
Cube calendar numbers
Credit: Marco Verch CC BY 2.0
A two-cube calendar, as shown in the picture, uses two cubes with digits painted on the faces to display the date. For dates in the range 1-9, a leading zero is used (&...
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22
votes
11
answers
3k
views
How powerful must this e approximation be?
This challenge was inspired by this non-challenge about the natural logarithm base \$e\$ and the following pandigital approximation to \$e\$ appearing on a Math Magic page:
$$\left|(1+9^{-4^{7×6}})^{3^...
- 3,707
20
votes
23
answers
2k
views
Borders of a Rectangular Matrix
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 ...
- 123k
12
votes
17
answers
2k
views
Compute cumulative means efficiently
Consider a sorted array of positive floating point numbers such as:
input = [0.22, 2.88, 6.35, 7.17, 9.15]
For each integer \$i\$ from 1 up to the last value in ...
- 1,812
24
votes
5
answers
2k
views
Add two real numbers ... probably
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 ...
- 96.5k
12
votes
15
answers
1k
views
The number of solutions to Hertzsprung's Problem
Hertzprung's Problem (OEIS A002464) is the number of solutions to a variant of the Eight Queens Puzzle, where instead of placing \$n\$ queens, you place \$n\$ rook-king fairy pieces (can attack like ...
- 8,588
14
votes
7
answers
1k
views
Gödel encoding - Part II (decoding)
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,...
- 3,239
31
votes
18
answers
3k
views
Gödel encoding - Part I
Related but different.
Part II
Taken from the book: Marvin Minsky 1967 – Computation:
Finite and Infinite Machines, chapter 14.
Background
As the Gödel proved, it is possible to encode with a unique ...
- 3,239
11
votes
7
answers
2k
views
Zahlen auf Deutsch! (Numbers in German)
Your task is to write a program that receives a base 10 number from 0 to 99 and outputs the German name of that number with non-ASCII characters replaced with ASCII equivalents.
German number names
<...
- 313
16
votes
7
answers
2k
views
How Super is this Prime?
A super prime is a prime whose index in the list of primes is also a prime:
...
- 1,155
8
votes
3
answers
571
views
Doors and guards
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 ...
- 3,239
13
votes
4
answers
1k
views
Is it a Frog List?
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...
- 123k
19
votes
56
answers
5k
views
Implement the `<=>` three-way comparison operator on numbers
In C++, there exists a a <=> b three-way comparison operator that, for numerical types, does the following:
If a < b, ...
- 8,588
0
votes
6
answers
417
views
Generate number from given range
Your function must accept three numbers in any order:
A signed real number (or ±Infinity) - The number (N) for which you have ...
- 1,473
15
votes
16
answers
1k
views
Imtiaz Germain Primes
Description
"Imtiaz Germain primes" is not a technical name in Mathematics, but my weird creation, in the memoir of the famous mathematician Sophie Germain. These primes can be generated by ...
- 1,732
16
votes
7
answers
1k
views
Largest Binary Area
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 ...
- 11.8k
11
votes
16
answers
986
views
Multibase Numbers
(Similar: Through the bases)
Normally, our number system is base ten, with the digits 0123456789. However, we can increase or decrease the base count (so ...
- 561
18
votes
24
answers
2k
views
Shortest code to generate all Pythagorean triples up to a given limit
Generate the shortest possible code in any programming language that can generate all Pythagorean triples with all values not exceeding a given integer limit. A Pythagorean triple is a set of three ...
- 1,732
10
votes
5
answers
386
views
Consolidate a 6-axis 2-dimensional Vector
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 ...
- 9,369
12
votes
71
answers
3k
views
Summing the Digits of a Number
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 ...
- 1,732
11
votes
5
answers
604
views
Whole Number Groups
Given a list of fractions, group them so that each group sums to a whole number. This should be done in such a way to maximize the number of non-empty groups.
You may assume a solution exists. Order ...
- 11.8k
12
votes
6
answers
609
views
Number Clusters
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 \$...
- 3,650
13
votes
16
answers
1k
views
Find opposite string
Your function must accept one string and return the opposite
The opposite string is a string where all characters go in reverse order, all letters are replaced with the opposite mirror letter from the ...
- 1,473
17
votes
19
answers
3k
views
Print all pandigital numbers
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 ...
- 11.8k
9
votes
15
answers
2k
views
Sum of numbers of arbitrary length
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 ...
- 1,473
22
votes
27
answers
3k
views
Sum of Consecutive Squares
Your task
Given a integer input, \$ n \$ (such that \$ n > 1 \$), decide whether it can be written as the sum of (at least 2) consecutive square numbers.
Test cases
Truthy:
...
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