Questions tagged [number]
A competition to solve a particular problem through the usage and manipulation of numbers.
1,150
questions
27
votes
13answers
3k views
Valid Badminton Score?
Introduction:
I saw there was only one other badminton related challenge right now. Since I play badminton myself (for the past 13 years now), I figured I'd add some badminton-related challenges. Here ...
17
votes
26answers
886 views
Calculating total slots
Given a list of jobs, which must be done in order, with each taking a slot to do, how long will it take to perform them all if after doing a job the same job cannot be done for the next two slots (...
26
votes
22answers
2k views
The Digit Triangles
Challenge:
Input: A positive integer \$n\$
Output:
Create a list in the range \$[1,n]\$, and join it together to a string (i.e. \$n=13\$ would be the string ...
-1
votes
1answer
107 views
Sort a list of Numbers as letters [closed]
So, you have a random list (random meaning it doesn't matter what order it is in) of numbers with a length of n, where n is a positive integer smaller than 1000 and ...
35
votes
52answers
9k views
Am I not good enough for you?
Background:
The current Perfect Numbers challenge is rather flawed and complicated, since it asks you to output in a complex format involving the factors of the number. This is a purely decision-...
34
votes
27answers
8k views
Could you please stop shuffling the deck and play already?
Challenge:
Input: A list of distinct positive integers within the range \$[1, \text{list-size}]\$.
Output: An integer: the amount of times the list is riffle-shuffled. For a list, this means the list ...
12
votes
10answers
631 views
New Order #1: How does this feel?
Introduction
Putting all positive numbers in its regular order (1, 2, 3, ...) is a bit boring, isn't it? So here is a series of challenges around permutations (reshuffelings) of all positive numbers.
...
70
votes
48answers
7k views
Is it a Cyclops number? “Nobody” knows!
Task:
Given an integer input, figure out whether or not it is a Cyclops Number.
What is a Cyclops number, you may ask? Well, it's a number whose binary representation only has one ...
30
votes
24answers
5k views
The (Easy) Road to Code
Input:
An integer \$n\$, which is guaranteed to be \$\ge3\$.
An integer \$d\$, which is one of \$[-1,0,1]\$.
Output:
A road of size \$n\$, which will be in a north-west direction if \$d=-1\$; a ...
12
votes
31answers
2k views
Sum integers in a string [duplicate]
Input
A string.
Output
The sum of all integers in the line.
Constraints
1≤Length of line≤500
Sample test Case
Input
the 5is 108 seCONd4 a
Output
...
12
votes
18answers
2k views
Jumping Numbers
A jumping number is defined as a positive number n which all pairs of consecutive decimal digits differ by 1. Also, all single digit numbers are considered jumping numbers. eg. 3, 45676, 212 are ...
asked Mar 1 '19 at 17:11
Luis felipe De jesus Munoz
9,7592 gold badges22 silver badges77 bronze badges
34
votes
5answers
8k views
Historical difference between `/` and `÷` in mathematical expressions
Introduction:
Inspired by a discussion that is already going on for many years
regarding the expression \$6÷2(1+2)\$.
With the expression \$6÷2(1+2)\$, mathematicians will quickly see that ...
77
votes
39answers
12k views
Am I a Rude Number?
For a while now, I've been running into a problem when counting on my fingers, specifically, that I can only count to ten. My solution to that problem has been to count in binary on my fingers, ...
21
votes
17answers
2k views
Square Root Distance from Integers
Given a decimal number k, find the smallest integer n such that the square root of n is ...
19
votes
25answers
3k views
23
votes
17answers
4k views
The real treasure was the numbers we made along the way
Your task is to write a program, function or snippet (yes, snippets are allowed) that simply outputs an integer. However, you must be able to separate your submission into prefixes that also produce ...
46
votes
24answers
6k views
Covering a Skyline with brush strokes
Given a non-negative integer skyline height list, answer how many uninterrupted 1-unit-high horizontal brush strokes are needed to cover it.
[1,3,2,1,2,1,5,3,3,4,2]...
2
votes
7answers
364 views
Countries by Area
Challenge
Given two non negative integers a < b, output all countries, from the below Top 100 Countries, where area is between ...
5
votes
2answers
621 views
A Multipurpose Quine
I personally love quines, but they all seem to be so... static. So why not create a quine that can do more.
Challenge
The challenge here is to create a quine that without any sort of input is a ...
11
votes
3answers
756 views
Trapped Knight Sequence
Introduction
Inspired by the very recent video The Trapped Knight - Numberphile, I came up with a challenge.
The trapped knight sequence is a finite integer sequence of length 2016, starting from 1, ...
18
votes
15answers
1k views
Spot all (anti)diagonals with duplicated values
Challenge:
Given a matrix input, determine the amount of diagonals and anti-diagonals with duplicated numbers.
So if we have a matrix like this:
...
10
votes
14answers
548 views
Prime Difference [duplicate]
Given an integer n, output the smallest prime such that the difference between it and the next prime is at least n.
For example, if n=5, you would output ...
1
vote
2answers
232 views
Work out \$x^y\$ using only addition and subtraction [duplicate]
The challenge is to implement a function or program that takes two numbers, \$x\$ and \$y\$ and return the result of \$x^y\$.
The program cannot use any other mathematical operation other than \$+\$ ...
24
votes
15answers
3k views
Matrix Jigsaw Puzzles
Input:
An integer n
Two equal-sized square matrices (with their width/height being a multiple of n)
Output:
One of two ...
27
votes
41answers
2k views
Enumerate each series of identical numbers in-place
Given a list of strictly positive integers, go through each distinct number and replace all occurrences of it with successive indices (zero or one based) of a new series.
Examples
...
7
votes
11answers
599 views
Mis-decode a date
Background
Inspired by a now deleted question by John Burger from which I quote:
Now obviously no human made this mistake. It's a mis-decode of something - perhaps the ISBN? My question is: ...
5
votes
2answers
499 views
Surreal Numbers
Surreal Numbers are one way of describing numbers using sets. In this challenge you will determine the value of a surreal number.
Intro
A surreal number consists of two sets: a left and right. The ...
10
votes
7answers
361 views
Approximate the proportion of integers with neighboring factors
If 1 is not counted as a factor, then
40 has two neighboring factors (4 and 5)
1092 has two neighboring factors (13 and 14)
350 does not have two neighboring factors
(out of its factors 2, 5, 7, 10, ...
1
vote
0answers
87 views
Sino-Korean numerals [duplicate]
The Korean language has two sets of numerals, a native Korean numerals and Sino-Korean numerals.
The native Korean numerals are mostly used for numbers under 100, such as age and time.
The Sino-...
28
votes
20answers
3k views
Convert to Suzhou numerals
Suzhou numerals (蘇州碼子; also 花碼) are Chinese decimal numerals:
0 〇
1 〡 一
2 〢 二
3 〣 三
4 〤
5 〥
6 〦
7 〧
8 〨
9 〩
They pretty much work like Arabic numerals, except ...
1
vote
4answers
225 views
Round the digits last digit, over and over
Challenge:
Given two inputs, x and y, round x to one less significant figure, then repeat until it has y number of unrounded digits left. (the decimal point does not count as a digit)
Input & ...
16
votes
7answers
696 views
Satisfying Rounding
Satisfying Rounding
You know when you're in science class, and asked to round to 2 sig figs, but your answer is 5.2501...? You should round to ...
22
votes
4answers
3k views
Golf a number bigger than Loader's number
As a follow up to Shortest terminating program whose output size exceeds Graham's number and Golf a number bigger than TREE(3), I present a new challenge.
Loader's number is a very large number, ...
13
votes
26answers
1k views
Self-contained powers
Given integer n, output the smallest exponent e greater than 1 such that n^e contains ...
32
votes
47answers
5k views
Print all lexicographically increasing numbers under 10000
A lexicographically increasing number is an integer whose digits are in strictly increasing order. Print all lexicographically increasing numbers under 10000.
Here are lines of the expected output:
...
0
votes
2answers
160 views
Number letter counts [closed]
If the numbers 1 to 5 are written out in words: one, two, three, four, five, then there are 3 + 3 + 5 + 4 + 4 = 19 letters used in total.
Output how many letters would be used if all the numbers from ...
7
votes
3answers
1k views
Largest Number in Brainfuck BigInt for each program length up to 50 instructions
This challenge is for the largest finite number you can get BrainFuck programs of given lengths to contain in memory.
We must use one of the BF versions that uses big integers for the cells rather ...
24
votes
26answers
2k views
Sort by Largest Digit(s)
Challenge:
Given a list of integer, sort descending by their single largest digit(s). The order for numbers with the same largest digit are then sorted by second largest digit, etc.
We ignore ...
15
votes
30answers
2k views
Upward and onward to greater glory!
May this challenge serve as (another) tribute to Stan Lee, who passed away aged 95.
Stan Lee has left us an invaluable legacy and a peculiar catch word: Excelsior. So here's a small challenge based ...
11
votes
9answers
1k views
Through Space and Time
Introduction:
In general we usually speak of four dimensions: three space dimensions for x, y, and ...
16
votes
50answers
2k views
Print the Lost numbers
As a big fan of the Lost TV series, I always got intrigued by the sequence of numbers that repetitively appears on the episodes. These numbers are:
\$ 4, 8, 15, 16, 23, 42\$ (A104101)
Using any ...
-1
votes
5answers
527 views
Fastest algorithm to output array containing all integers in range excluding duplicate digits
Input is a single integer in ascending digit order.
The only valid inputs are:
12
123
1234
...
7
votes
12answers
854 views
Decimal Digit Truncating
Input:
A decimal
Output:
The input truncated
How to truncate them?
The integer part of the input will remain the same. The decimal part of the input will be truncated based on the lowest digit in ...
6
votes
4answers
158 views
Seeking Substantial Subcollections
(thanks to @JonathanFrech for the title)
Challenge
Write a program or function that, given a collection of positive integers \$S\$ and a positive integer \$n\$, finds as many non-overlapping ...
5
votes
1answer
111 views
Minimum 1's to get 1-expression for n [duplicate]
Background
Challenge is inspired by this question.
The 1-expression is a formula that in which you add and multiply the number 1 any number of times. Parenthesis is allowed, but concatenating 1's (e....
-4
votes
20answers
418 views
Array indexes to number and number reversed
Given an input array having minimum length 2 and maximum length 9 having any initial values output an array having length ...
28
votes
37answers
9k views
IP address or not?
Your network scanning tool is annoyingly picky about input, and immediately crashes if you feed it an IPv4 address that contains improper characters or isn't properly formatted.
An IPv4 address is a ...
37
votes
53answers
9k views
List all possible titles for the Anno games
In the Anno video game series there are 6 games with a 7th one announced for early 2019. Their titles always feature a year in a specific pattern:
...
24
votes
27answers
2k views
Minimal Power Root
The minimal power iteration of a number \$n\$ is defined as follows:
$$\text{MPI}(n):=n^{\text{min}(\text{digits}(n))}$$
That is, \$n\$ raised to the lowest digit in \$n\$. For example, \$\text{MPI}(...
33
votes
24answers
6k views
Can the number be split into powers of 2?
Yesterday while playing with my kid I noticed the number in his toy train:
So we have $$4281$$ that can be split into $$4-2-8-1$$ or $$2^2-2^1-2^3-2^0$$
So simple challenge: given a non-negative ...
