75
votes
The first n numbers without consecutive equal binary digits
Python 2, 36 bytes
lambda n:[2**i*2/3for i in range(n)]
Try it online! Explanation: The binary representation of \$\frac{2}3\$ is ...
- 166k
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
61
votes
How on earth did llhuii output the Evil Numbers in 42 bytes of Python?
This isn't the same solution as llhuii's, but it's also 42 bytes long.
n=0;exec'print n;n^=(n^n+2)%3/2;n+=2;'*400
Try it online!
Thanks to @JonathanFrech, we're ...
- 210k
55
votes
Fizz Buzz to Text
C, 59 bytes
i;f(char*s){while(*s&3?*s&9||(i+=i+*s%5):putchar(i),*s++);}
Magic numbers, magic numbers everywhere!
(Also, C shorter than Python, JS, PHP, ...
- 71.4k
45
votes
How on earth did llhuii output the Evil Numbers in 42 bytes of Python?
Getting 39 bytes
This is an explanation of how I got a 39-byte solution, which Dennis and JonathanFrech found separately as well. Or, rather, it explains how one could arrive at the answer in ...
- 144k
42
votes
i love yOu i lOve you i love yOu!
Jelly, 41 40 35 33 bytes
Thanks to @Dennis for making the end ṖṖCG! (complement C = 1-x in ...
- 104k
42
votes
Where's the 0xBEEF?
vim, 126 80 77 76
/\v1011\_.{9}(1110\_.{9}){2}1111<cr>:exe'norm Go'.join(getpos('.'))<cr>xxdawhPXXd{
Expects input in the form
...
- 71.4k
42
votes
Find the number of leading zeroes in a 64-bit integer
x86_64 machine language on Linux, 6 bytes
0: f3 48 0f bd c7 lzcnt %rdi,%rax
5: c3 ret
Requires Haswell or K10 or ...
- 7,457
42
votes
Accepted
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
35
votes
31
votes
Bit run rundown
Python 2, 46 45 bytes
f=lambda n,k=1:`k`in bin(n^n/2)and-~f(n,k*10)
Try it online!
How it works
By XORing n and n/2 (dividing by 2 essentially chops off the ...
- 210k
31
votes
Is the number binary-heavy?
x86 Machine Code, 15 14 bytes
F3 0F B8 C1 0F BD D1 03 C0 42 2B D0 D6 C3
This is a function using Microsoft's __fastcall calling convention (first and only ...
- 451
30
votes
Accepted
Where's the 0xBEEF?
Jelly, 20 17 16 bytes
ṡ€4ḄZw€“¿ÇÇБĖUṀ
Input is in form of a Boolean matrix, output is the 1-based index pair (Y, X).
Try it online! or verify all test cases.
...
- 210k
30
votes
Accepted
29
votes
28
votes
In how many bits do I fit
x86 Assembly, 4 bytes
Assuming Constant in EBX:
bsr eax,ebx
inc eax
EAX contains the number of bits necessary for Constant.
...
- 399
26
votes
Only Even Bytes
GS2, 4 bytes
dΦ("
Try it online!
Hexdump
0000000: 64 e8 28 22 d.("
How it works
...
- 210k
25
votes
Calculate the longest series of 1's in an integer's binary value
JavaScript (ES6), 33 32 bytes
f=x=>x&(k=x>>1)?f(x&k):k&&1+f(k)
Try it online!
JavaScript (ES6), 41 40 36 34 bytes
Saved 4 bytes ...
- 188k
25
votes
Find the number of leading zeroes in a 64-bit integer
Hexagony, 78 70 bytes
2"1"\.}/{}A=<\?>(<$\*}[_(A\".{}."&.'\&=/.."!=\2'%<..(@.>._.\=\{}:"<><$
Try it online!
Isn't this challenge ...
- 17.2k
24
votes
Is it a Cyclops number? "Nobody" knows!
Python 2, 30 bytes
lambda n:(2*n^2*n+3)**2==8*n+9
Try it online!
Note that 2*n^2*n+3 is the bitwise xor of ...
- 144k
23
votes
Numbers with multiple runs of ones
Python, 48
lambda n:[i for i in range(2**n)if'01'in bin(i)]
I had been vastly overthinking this. We just need to check if the binary expansion contains ...
- 144k
23
votes
JFor? More like XNor
Python, 34 bytes
lambda a,b:bin(a&b).count('01')==1
Try it online!
Although this doesn't use xor, I'm xnor.
- 144k
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
22
votes
Where's the 0xBEEF?
JavaScript (ES6), 63 60 56 bytes
s=>[(i=s.search(/1011.{9}(1110.{9}){2}1111/))%13,i/13|0]
Takes input as a 155-character space-delimited string of 12 12-digit ...
- 166k
22
votes
Complex Binary Numbers
MATL, 7 bytes
BJ*Y'^s
Try it online!
How it works
Consider input 4538 for example.
...
- 104k
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.
...
- 7,862
22
votes
A bit, a nibble or byte?
Python, 39 bytes
f=lambda n:4**(n>1)*(n<16)or 2*f(n**.5)
Counts how many times one must take the square root for n to ...
- 144k
Only top scored, non community-wiki answers of a minimum length are eligible