63
votes
Accepted
Binary to decimal converter
Jelly, 5 bytes
DḤ+¥/
Try it online!
Explanation
The cast
D is a monad (single argument function): digits, turning ...
- 68.1k
38
votes
Output numbers up to 2^n-1, "sorted"
Python, 53 bytes
f=lambda n,i=1:n*[f]and[i]+f(n-1,2*i)+i%2*f(n-1,i-~i)
Try it online!
The recursive function generates the sorted list as a pre-order walk down ...
- 144k
27
votes
Find the polynomial
Jelly, 3 bytes
‘b@
Try it online!
Returns the polynomial as a list of coefficients.
Since we know the polynomial has non-negative integer coefficients, f(b) ...
- 71.4k
26
votes
What base is this number in?
Python, 27 22 bytes
lambda s:(max(s)-8)%39
This requires the input to be a bytestring (Python 3) or a bytearray (Python 2 and 3).
Thanks to @AleksiTorhamo for ...
- 210k
26
votes
Accepted
23
votes
Accepted
Numbers that are actually letters
Pyth, 43 - 40 = 3 bytes
?&[email protected]"Mix"%"Only %sers"?K"lett""numb
Test suite
This achieves the bonus. Only numbers and ...
- 42k
22
votes
Accepted
16-bit binary grid
J, 26 bytes
(' ';' # '){~4 4$_16{.#:
An anonymous verb. Thankfully, J is very good at drawing boxes. Let's try it out:
...
- 68.1k
22
votes
Binary to decimal converter
Python 2, 49 37 31 30 Bytes
Now this will take a binary number in a decimal representation, since Python can handle arbitrarily large integers.
...
- 7,852
22
votes
What is the reverse (binary) bit number?
Python, 29 bytes
lambda n:int(bin(n)[:1:-1],2)
Try it online!
This is an anonymous, unnamed function which returns the result.
First, ...
- 14.6k
21
votes
Reverse and square
Mathematica, 42 21 bytes
Thanks to alephalpha for halving the score.
#~IntegerReverse~2^2&
The actual reason I did this in Mathematica was because I wanted ...
- 196k
21
votes
What base is this number in?
Python, 25 bytes
lambda x:int(max(x),36)+1
Defines a lambda that takes the string x. Finds the largest digit in the string (...
- 7,800
21
votes
The best base is 10... Let's reach it!
Mathematica, 56 bytes
#//.x_/;(b=Max[d=IntegerDigits@x]+1)<11:>d~FromDigits~b&
Try it online! (Using Mathics.)
I thought I'd check out what the ...
- 196k
20
votes
Convert a 32 bit binary IPv4 address to its quad-dotted notation
x86-16 machine code, IBM PC DOS, 54 47 45 bytes
Binary:
...
- 11.8k
19
votes
Converting "0xUsernames"
JavaScript (ES6), 15 bytes
s=>'0x1'+s-0||s
How it works
'0x1'+s converts the input into a literal hexadecimal string with ...
- 49.9k
18
votes
Output numbers up to 2^n-1, "sorted"
Jelly, 6 bytes
Ḷ2*ẆS€
This qualifies for the imaginary bonus.
Try it online!
How it works
...
- 210k
18
votes
Does base n have any Rotate-Left-Double numbers?
05AB1E, 6 5 bytes
ÍD<&Ā
-1 byte thanks to @xnor and @Noodle9.
Try it online or verify the first \$[2,100]\$ test cases.
Explanation:
...
- 123k
17
votes
Zeroes in interval
Jelly, 1 byte
¬
This uses base k+2, in which case there's a single 0 iff i is 0. It takes ...
- 21.4k
17
votes
Accepted
What base is this number in?
Jelly, 4 bytes
ṀØBi
Requires uppercase. Try it online! or verify all test cases.
How it works
...
- 210k
17
votes
What is the reverse (binary) bit number?
Python, 29 bytes
lambda n:int(bin(n)[:1:-1],2)
Try it online
- 23.3k
17
votes
French license plates
Pure Bash (no external utils), 64
2 bytes saved thanks to @NahuelFouilleul
x={A..Z}
eval f=($x$x-%03d-$x$x)
printf ${f[$1/1000]} $[$1%1000]
Try it online! - ...
- 71.8k
16
votes
Numbers that are actually letters
Pyth, 6 bytes
!-.HQG
.HQ # Converts the input to hexadecimal
- G # Deletes all letters
! # If empty, output True, else False
Test it here
- 44.3k
16
votes
Smallest Zeroless Base
Pyth, 6 bytes
f*FjQT
Verify all the test cases.
How it works
f*FjQT ~ Full program.
f ~ First positive integer where the condition is truthy.
jQT ~ ...
- 42.3k
16
votes
Accepted
Take a byte out of it!
Jelly, 6 bytes
BḄ-8ƤṀ
A monadic link taking a number and returning a number.
Try it online!
How?
Uses a nice quick, Ƥ, ...
- 104k
15
votes
14
votes
16-bit binary grid
JavaScript (ES6), 102
... or 96 using return instead of console.log.
Test running the snippet below in an EcmaScript 6 ...
- 32k
14
votes
14
votes
Accepted
Simplify binary
Pyth, 20 16 bytes
u?-GTG`u+yNsTG0z
4 bytes thanks to Jakube
Half of the code (u+yNsTG0) is simply the base conversion code.
...
- 42k
14
votes
Accepted
A multiplication table for the Cheela
Pyth, 27 * 0.8 = 21.6
VSQsm.[\ 4jkXj*dNQrT99rG1SQ
Try it online: Demonstration
Explanation:
...
- 21.9k
14
votes
Convert a number to Hexadecimal
Turing Machine Code, 412 bytes
As usual, I'm using the rule table syntax defined here. You can test it on that site or, alternatively, using this java implementation.
...
- 11.9k
14
votes
Binary to decimal converter
05AB1E, 6 bytes
Code:
$¦v·y+
For the explantion, let's take the example 101010. We start with the number 1 (which is represented by the first digit). After that,...
- 44.3k
Only top scored, non community-wiki answers of a minimum length are eligible