Questions tagged [base-conversion]
Conversion of numbers between positional numeral systems. Most common systems are decimal, binary, hexadecimal etc.
179
questions
19
votes
25
answers
1k
views
Carry-less sum given a base b
Given a list of positive integers \$\mathcal I=I_1,I_2,I_3,...,I_n\$ and a base \$b>1\$ return their "carry-less sum", i.e. represent \$\mathcal I\$ in base \$b\$ and sum digit-by-digit ...
- 9,258
19
votes
30
answers
2k
views
Convert from variable-width Two's Complement to Integer
Take an input, and convert it from Two's Complement notation (binary where the first bit is negated, but the rest are taken as normal) into an integer (in a somewhat standard output form). Input can ...
- 1,306
25
votes
16
answers
3k
views
Convert to base i - 1
Given \$ i = \sqrt{-1} \$, a base-\$ (i - 1) \$ binary number \$ N \$ with \$ n \$ binary digits from \$ d_{0} \$ to \$ d_{n - 1} \$ satisfies the following equation.
$$ N = d_{n - 1} (i - 1) ^ {n - 1}...
- 2,273
12
votes
20
answers
1k
views
Convert a string of ASCII characters to base-3 equivalents
Task similar to this one. Take a string of ASCII characters and convert it to base-3 equivalents separated by a space.
For example:
Hello, world!
Should be ...
- 1,805
12
votes
14
answers
1k
views
Lowest integer with no common digits between given bases
Challenge
Given a list of bases for positional numeral systems as input, output the lowest positive integer that when represented in those bases they have no common digits. The input list can be ...
- 4,589
3
votes
11
answers
482
views
Concatenate characters' indexes in the alphabet in the given numeral system
Given a word, get the indexes of each letter in the alphabet.
For example: uncopyrightable becomes: ...
- 473
17
votes
11
answers
2k
views
Write a number in overflowed binary
We all know how binary conversion works: the sequence of bits
$$ b_1, b_2, ..., b_{n-1}, b_n $$
encodes the number
$$ b_1 \times 2^{n-1} + b_2 \times 2^{n-2} + ... + b_{n-1} \times 2^1 + b_n \times 2^...
- 22.6k
13
votes
9
answers
998
views
Bijective meets mixed base
Background
A bijective base \$b\$ numeration, where \$b\$ is a positive integer, is a bijective positional notation that makes use of \$b\$ symbols with associated values of \$1,2,\cdots,b\$.
...
- 66.1k
8
votes
27
answers
2k
views
How long is the number in this base?
Given a positive integer \$n\$ and another positive integer \$b\$ (\$1 < b < 36\$), return the number of digits/length of \$n\$ in base \$b\$
...
- 113
13
votes
9
answers
693
views
Convert to a non-adjacent form
Consider a form of binary where digits can be any of \$1\$, \$0\$ and \$-1\$. We'll still call this "binary" because we convert the digits from base two. For example,
$$\begin{align}
[1, 0, -...
- 48.1k
19
votes
3
answers
378
views
A multiple of n in every base!
In November 2019, Alon Ran published a particularly lovely sequence in the OEIS, A329126:
\$a(n)\$ is the lexicographically earliest string of digits which yields a multiple of \$n\$ when read in any ...
- 8,117
11
votes
13
answers
709
views
'Plane' the numbers in any base!
Inspired by this Numberphile video.
What is planing?
In order to 'plane' a sequence of digits, you need to:
Identify the lengths of the 'runs' (adjacently repeated digits) in the sequence. Non-...
- 2,309
32
votes
15
answers
2k
views
Compute the generalised XOR
The goal of this challenge is to generalise the bitwise XOR function to other bases. Given two non-negative integers \$ x \$ and \$ y \$, and another integer \$ b \$ such that \$ b \geq 2 \$, write a ...
- 391
5
votes
12
answers
924
views
Base-ically Guard
Base: part 1
This is part 2, Strongly suggest you go try out the first one if you haven't tried it.
Story
As one of the solvers, You've managed to get to the door of the base heaven. In front of the ...
- 1,407
8
votes
17
answers
1k
views
Base-ically god
Story
The god of base is opening heaven’s gate for mortals to join the base party. You, as one of the believers, want to follow their steps to ascend to heaven.
But not everyone can get in.
The god ...
- 1,407
25
votes
33
answers
2k
views
Count the trailing zeros
Given two positive integers \$n\$ and \$b\$, such that \$n > 2\$ and \$n > b > 1\$, count the trailing zeros when converting \$n\$ to base \$b\$. Your program should be able to handle any ...
- 48.1k
11
votes
3
answers
346
views
Help me count the Omer
During the 49 days between Passover and Pentecost, Jewish liturgy provides four numerical problems that I've here phrased as code golf problems.
Input/Arguments
These four, in any order, and by any ...
- 28.3k
23
votes
27
answers
2k
views
Based Palindromes
A palindromic number, as a refresher, is any number which reads the same forward as backwards. However, what about palindromes in other bases?
Input
Any integer b ...
- 504
14
votes
12
answers
921
views
Compute the Redwolf Checksum™ of some data
I will preface this by saying that I made this for fun; I have absolutely no formal knowledge on cryptography or error correction. Do not use this algorithm in anything remotely important.
I was kind ...
- 17.9k
21
votes
25
answers
1k
views
Possible binaries sum
This challenge is inspired by the AoC 2020, Day 14 - Part II, created by Eric Wastl and his team, which asks to output the possible binary values from a bitmask.
Let's say we've a bitmask like ...
- 2,860
23
votes
27
answers
2k
views
Perfect radicals
Given a positive integer number \$n\$ output its perfect radical.
Definition
A perfect radical \$r\$ of a positive integer \$n\$ is the lowest integer root of \$n\$ of any index \$i\$:
$$r = \sqrt[i]{...
- 9,836
26
votes
17
answers
3k
views
Convert negadecimal to decimal (and back)
Negadecimal, also known as base -10, is a non-standard positional numeral system.
Take the number \$1337_{10}\$. In decimal, this has the value one thousand three hundred thirty seven, and can be ...
- 17.9k
23
votes
36
answers
2k
views
Display the exponent from a binary floating point number as a decimal value
Had my software final exams recently, one of the last questions had me thinking for a while after the exam had finished.
Background
IEEE754 numbers are according to the below layout
The exponent is ...
- 399
18
votes
7
answers
718
views
Combinatorial Decomposition
In the body of this challenge, \$\begin{pmatrix}n\\k\end{pmatrix}\$ is used to represent the number of combinations of \$k\$ elements of \$n\$, also written as \$\frac{n!}{k!(n-k)!}\$ or \$n\mathrm{C}...
- 2,009
11
votes
8
answers
1k
views
Scientific notation in Base-16
Input a scientific notation number (base 10), output scientific notation in base 16 (as defined below).
Details
In scientific notation, all non-zero numbers are written in the form
$$ m \times 10^n $$
...
- 30.8k
17
votes
11
answers
2k
views
The Double-Castle Numbers™
Introduction
A double-castle number™ is a positive integer number that has a pattern of $$\underbrace{a\cdots a}_{m\text{ }a\text{s}}b\underbrace{a\cdots a}_{m\text{ }a\text{s}}b\underbrace{a\...
- 6,088
10
votes
2
answers
398
views
Inverse of Conway base 13 function in \$\mathbb{Q}\$
(The \$\mathbb{Q}\$ in the title means rational numbers.)
Background
Conway base 13 function is an example of a strongly Darboux function, a function that takes every real number on any open ...
- 66.1k
13
votes
9
answers
434
views
Minimal Rotate-Right-Double numbers in base n
Task
For a given base \$n \ge 3\$, find the smallest positive integer \$m\$, when written in base \$n\$ and rotated right once, equals \$2m\$. The base-\$n\$ representation of \$m\$ cannot have ...
- 66.1k
19
votes
22
answers
4k
views
Convert to and from Base 94
The challenge
Make 2 programs which convert decimal to and from base 94, or a bidirectional program.
Base 94?
Base 94 is like any other base, but instead of 0 to 9 and letters, it uses ASCII ...
- 2,615
9
votes
12
answers
376
views
Does base n have any Rotate-Left-Double numbers?
Task
A Rotate-Left-Double number in base \$n\$ is a number \$m\$, when its base-\$n\$ digits are rotated left once, equals \$2m\$. The base-\$n\$ representation of \$m\$ cannot have leading zeros.
...
- 66.1k
29
votes
43
answers
6k
views
Convert a 32 bit binary IPv4 address to its quad-dotted notation
Challenge
Write a program or function that converts a 32 bit binary number to its quad-dotted decimal notation (often used for representing IPv4)
Quad-dotted decimal
A quad-dotted decimal is formed ...
- 1,599
16
votes
16
answers
1k
views
Find the length of a number's "base-jumping" path
Consider a positive integer N written in base b. A sequence is generated from this number by finding the largest digit ...
- 7,259
31
votes
4
answers
4k
views
How close are we, really?
Please note: this is a restricted-source challenge — see details below!
Each natural number \$n\$ has 10 faces: its decimal representations in bases \$1\$ through to \$10\$. For example, the 10 faces ...
- 48.1k
-1
votes
2
answers
276
views
Mirror, Mirror, on the wall. Who's the fairest of them all?
Well, you know it's Snow White, and the evil Queen is at it again. Will Snow White be saved? Will she fall asleep once again? Will the Prince find her?
Challenge:
Given an arbitrary number (>= 2) ...
- 281
44
votes
30
answers
9k
views
French license plates
Sandbox
French License Plates
French license plates come in a sequential order, following a specific pattern of numbers and letters : AB-012-CD
Challenge
Write ...
- 1,013
18
votes
19
answers
2k
views
Simplification of numbers
How, you can’t remember the 6 or 7-digit phone number that appeared on the TV screen for a second?! Using the special technique described below, you will turn into a walking phonebook!
Obviously, the ...
- 605
-1
votes
11
answers
452
views
Convert alphanumeric (base-36) sentences into hexadecimal (base-16) sentences
I use "sentence" here loosely to mean "any sequence of words separated by spaces" and "words" to mean "sequences of alphanumeric (hexatrigesimal) characters unseparated by spaces".
Conversion is from ...
- 642
-2
votes
11
answers
371
views
Convert a number into "bracket" numerals
"Bracket" numerals are a type of 'numerals' I made up once, and thought would be a nice challenge here. Basically, you convert the input number into base 6, and then transliterate the ...
- 123
-1
votes
13
answers
543
views
Find how "smooth" a number is based on binary
I haven't been on PP&CG for a while, so I thought I would post something!
Your task is to find how "smooth" a natural number is. Your method is to:
1: Convert the number to binary
2: Find the ...
- 123
1
vote
1
answer
238
views
Pumping quine radix
Inspired (you don't need to know them for this challenge) by the Pumping Lemma for various languages, I propose the following challenge:
choose some basis \$B \geq 2\$ and an integer \$n \geq 0\$
...
- 16.5k
23
votes
29
answers
2k
views
Digital Sumorial
Given an input n, write a program or function that outputs/returns the sum of the digital sums of n for all the bases 1 to ...
- 7,638
0
votes
7
answers
746
views
convert decimal to duodecimal
The task is to convert a string representing a number in decimal (base 10) representation to duodecimal (base 12). The input is thus a string, the output should be printed.
The input number can be ...
- 125
8
votes
5
answers
799
views
Permutation Encoding
Write a program which can encode text to avoid reusing characters, and convert back.
Both normal and encoded forms are restricted to a particular character set: the space character ...
- 409
30
votes
18
answers
2k
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 ...
- 413
20
votes
34
answers
3k
views
Increment base-36 strings
This is a code golf version of a similar question I asked on stack earlier but thought it'd be an interesting puzzle.
Given a string of length 10 which represents a base 36 number, increment it by one ...
- 331
24
votes
33
answers
4k
views
ASCII art uncompression from a base-n number
This is inspired by an 05AB1E answer by Magic Octupus Urn.
Given two arguments, a positive integer and a string/list of characters:
Translate the number to base-n, where n is the length of the ...
- 46.4k
2
votes
2
answers
150
views
Divide them all [duplicate]
A Math.SE user have a funny game explained as such:
Pick a random positive integer X.
Add +1, 0, -1 to make it divisible by 3Keep track of how much you've added and subtracted. That is your "...
- 287
1
vote
2
answers
211
views
Hexadecimal, octal, binary, oh my! [duplicate]
This is a code golf puzzle: shortest byte count wins. The program should do the following (standard loopholes obviously forbidden):
Input a hexadecimal number
Convert to octal
Then interpret the ...
- 17.9k
-10
votes
28
answers
485
views
What are these letters?
So what might be the shortest language for this simple task?
Task:
You are given an input of type String - the string is a ...
- 792
29
votes
44
answers
3k
views
Up go the bits!
Given an integer N perform the following steps: (using 9 as an example).
Receive input N. (9)
Convert N from base10 to base2. (...
- 2,896