Questions tagged [arithmetic]
Challenges related to elementary arithmetic.
13
votes
24answers
835 views
Standardize the Samples (Compute the z-Score)
Given a list of floating point numbers, standardize it.
Details
A list \$x_1,x_2,\ldots,x_n\$ is standardized if the mean of all values is 0, and the standard deviation is 1. One way to compute this ...
14
votes
19answers
3k views
How much candy can you eat?
Credit to Geobits in TNB for the idea
A post without sufficient detail recently posited an interesting game:
2 children sit in front of an array of candy. Each piece of candy is numbered 1 to ...
-3
votes
6answers
123 views
Measuring Mountains [duplicate]
Sum-It is a language I created (quite late) for the Language Design Contest in TNB, for which the theme was "Range". Naturally I interpreted this as "Mountain Range" and created a language about ...
19
votes
38answers
2k views
Given an input, print all exponents where the base and power sum to the input
So this is my first challenge on this site.
What this challenge is is that you input a number, and your code spits out numbers which can be calculated as an exponent. The sum of the exponent and base ...
19
votes
13answers
1k views
Dirichlet Convolution
The Dirichlet convolution is a special kind of convolution that appears as a very useful tool in number theory. It operates on the set of arithmetic functions.
Challenge
Given two arithmetic ...
19
votes
27answers
3k views
Strange Addition
Challenge
Calculate the strange sum of two natural numbers (also known as lunar addition):
Given A=... a2 a1 a0 and ...
17
votes
19answers
2k views
The Written Digits Sequence
Here's a reasonably trivial sequence which is not in the Online Encyclopedia of Integer Sequences.
Start with an empty sequence then define each term as the number of characters required to write out,...
2
votes
13answers
436 views
Validate a barcode [duplicate]
A barcode of EAN-13 symbology consists of 13 digits (0-9). The last digit of this barcode is its check digit. It is calculated by the following means (the barcode ...
10
votes
7answers
631 views
Whose neighbours are hostile?
Introduction
For the purposes of this challenge, we will define the neighbours of an element \$E\$ in a square matrix \$A\$ (such that \$E=A_{i,j}\$) as all the entries of \$A\$ that are immediately ...
7
votes
17answers
547 views
Extract and Divide
Challenge
For a given positive integer \$n\$:
Repeat the following until \$n < 10\$ (until \$n\$ contains one digit).
Extract the last digit.
If the extracted digit is even (including 0) multiply ...
14
votes
15answers
1k views
Missing numbers in arithmetic sum
Challenge
Giving a valid arithmetic sum with some missing numbers, output the full expression.
Example:
...
29
votes
18answers
1k views
Custom Number Base Converter
The powers that be want to be able to quickly convert any number they have into their own number base using any format they would like.
Input
Your program must accept 3 parameters.
Number: The ...
18
votes
21answers
2k views
Divide the work
There is a job which can be decomposed into x equally-sized smaller tasks. You have a team of size y <= x, where every member ...
17
votes
34answers
951 views
Calculate power series result [duplicate]
Related: Calculate Power Series Coefficients
Given a positive integer \$X\$ and a max exponent (Also a positive integer too) \$N\$ calculate the result of a power series. Example:
$$X^0+X^1+X^2+\...
21
votes
2answers
407 views
Subset Sum Orderings
A set of n positive numbers has 2^n subsets. We'll call a set "nice" if none of those subsets have the same sum. ...
21
votes
2answers
566 views
Double a number's continued fraction
Your task is, given x, output 2*x. Easy right!? But there's a catch: x will be given as a (...
16
votes
31answers
1k views
Recover the power from the prime power
It seems that many people would like to have this, so it's now a sequel to this challenge!
Definition: a prime power is a natural number that can be expressed in the form pn where p is a prime and n ...
13
votes
32answers
2k views
Recover the prime from the prime power
Definition: a prime power is a natural number that can be expressed in the form pn where p is a prime and n is a natural number.
Task: Given a prime power pn > 1, return the prime p.
Testcases:
<...
4
votes
1answer
313 views
Pair and sort from two integer lists
You are given two arbitrary integer lists, e.g. [-10, 99, -6, 43], [100, 32, 44]. You are to pick one integer from each list and ...
7
votes
4answers
846 views
Insulate the Window Glass and Foil of your house
Introduction:
The best options for the glass of your house will:
1. Let through as little heat as possible in both directions (insulation-value Ug).
(2. Let ...
9
votes
2answers
433 views
Interpreted arithmetic
A little known fact is that if you turn on enough language extensions (ghc) Haskell becomes a dynamically typed interpreted language! For example the following program implements addition.
...
3
votes
0answers
161 views
Make Three from One [duplicate]
Given a single digit integer and a three digit integer, output a mathematical formula that uses only the single digit and a given list of operators to equal the three digit integer.
Input: A one ...
11
votes
1answer
359 views
Not just a four fours puzzle
In this variant of the Four fours puzzle your should use up to x x's (and no other number) and a defined set of operations to ...
-1
votes
1answer
190 views
Find the longest uninterrupted arc in N dimensions
See similar question for 2D case: Find the longest uninterrupted arc
The challenge here is to find the longest uninterruped great circle arc around a unit hypersphere in N dimensions, with a random ...
5
votes
3answers
332 views
Find the longest uninterrupted arc
The challenge here is to find the longest uninterruped arc around a unit circle with a random amount of points distributed in random positions around it.
Here is a diagram to assist my explanation:
...
20
votes
5answers
1k views
Golfing out the haters
The setup:
A social network reports the number of votes a post has in two ways: the number of net upvotes (total upvotes - total downvotes), and the % of votes that were upvotes, rounded to the ...
7
votes
2answers
189 views
Minimal Triangles
Make an upside down triangle of positive integers. Every number in the triangle must be distinct. Each number is the summation of its two parents (similar to how Pascal's triangle is constructed, but ...
5
votes
27answers
1k views
Simple Factorial Challenge [duplicate]
In light of today's date...
A factorial of a number n, is the product of all the numbers from 1 to n inclusive.
The Challenge
Given an integer n where 0 <= n <= 420, find the sum of the ...
15
votes
12answers
749 views
Number of surjections
Task
Given 2 positive integers n and k, where n > k, output the number of surjections ...
11
votes
48answers
3k views
Integer logarithms
Given integers N , P > 1 , find the largest integer M such that P ^ M ≤ N.
I/O:
Input ...
13
votes
13answers
1k views
32
votes
24answers
4k views
Sum of five cubes
Given an integer, output five perfect cubes whose sum is that integer. Note that cubes can be positive, negative, or zero. For example,
...
25
votes
30answers
4k views
Zero-sum counting
Write a program or function that given n ≥ 1 returns the number of solutions to ±1 ± 2 ± 3 ± ... ± n = 0.
For n = 6 there are no solutions, so the answer is 0. For n = 4 there are ...
14
votes
30answers
3k views
Two steps forward and one step back
Let's say I'm ten steps away from my destination. I walk there following the old saying, "Two steps forward and one step back". I take two steps forward, one back, until I'm standing exactly on my ...
22
votes
24answers
2k views
Ten-pin bowling score - World Bowling edition
World Bowling scoring
Many people have gone to their local bowling center to play a few games of bowling, and many people continue to struggle to calculate their scores. World Bowling has introduced ...
25
votes
3answers
1k views
Golf A Free Lunch
Find a maximally profitable sequence of exchanges given an exchange rate table.
As an example consider the currencies Ariary (your home currency), Baht, Cedi, and Denar where the rate from one to ...
19
votes
26answers
1k views
Given a number, print out its “collective sum”
Given a number as input, print out its collective sum
What is a collective sum?
Consider the number 13214, the input
Looping through each of the digits starting ...
-5
votes
45answers
843 views
Quartic Summation
Guidelines
Task
Given two non-negative integers, find the sum of both numbers... to the power of 4.
Examples
2, 3 -> 97 (2^4 + 3^4 = 97)
...
26
votes
22answers
2k views
Diluted Integer Sums
A positive integer can be diluted by inserting a 0 between two bits in its binary expansion. This means that an n-bit number has ...
28
votes
8answers
2k views
Find number of ones to get a number using + and *
Introduction
Your goal is to find the least number of ones you need to add or multiply together to get the input value, this is A005245.
Input
One positive integer N.
Output
The smallest number ...
18
votes
12answers
2k views
Olympic Rings Sequence
Challenge:
Given an index integer n, either output the n'th item in this sequence, or output the sequence up to and including ...
6
votes
3answers
283 views
Accumulate some L.s.d
Prior to the decimalisation of Sterling in February 1971, a pound (£ - from Roman libra) comprised 20 shillings (s - solidus), each of 12 pennies (d - denarius). Additionally, until 1960, each penny ...
24
votes
61answers
3k views
The Non-Zero Digital Product Challenge
Originally the Multiplicative digital root
Challenge
Basically do what the title says
Method
Given a positive integer 1 <= N <= 100000000 through one of our standard input methods, multiply ...
11
votes
10answers
1k views
Create an N-Dimensional Simplex (Tetrahedron)
The Simplest N-Dimensional shape one can create for any dimension is a Simplex, and this is a set of N+1 points that are all equal distance away from eachother.
For 2 dimensions, this is an ...
11
votes
15answers
826 views
Encrypted In Numbers!
The Problem:
Two enemy secret agents have devised a wonderful (for you) method of communication!
Here’s how the encryption process works:
1) Take the ascii equivalents of each letter. (No spaces, ...
14
votes
6answers
723 views
Match the Striking Clock
Introduction:
At home we have a clock that strikes the stated amount at each hour, but also strikes once at every half-hour. So from 0:01 to and including 12:00 it strikes in this order:
...
15
votes
8answers
2k views
Be as evil as possible
Introduction
This is a follow-up of this challenge where you're taking the role of that person's evil twin. Being evil you don't want to maximize your share, but rather be as unfair as possible and ...
22
votes
30answers
2k views
What is the missing number (divisibility by 9)
Challenge
Given a whole number divisible by 9 and one missing digit, find the missing digit.
The missing digit may be represented by any character other than the digits 0-9 as long as it is ...
2
votes
6answers
196 views
52 Week Challenge [duplicate]
The 52 week challenge is a way to save money. For example, Week 1, you save $1.00. Week 2 you save $2.00, and it continues through the year, adding one more dollar to each week’s savings goal. By Week ...
34
votes
21answers
3k views
Easy-to-multiply numbers
Your task is to determine whether two numbers are easy to multiply. This means that their base-10 long multiplication doesn't have any carrying (regrouping) between place values, looking at both the ...
