59
votes
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
41
votes
Remove surrounding zeroes of a 2d array
Wolfram Language (Mathematica), 42 bytes
#&@@CellularAutomaton[{,{},0{,}},{#,0},0]&
Try it online!
Cellular automata are indeed the answer to life, the ...
- 13.8k
31
votes
Accepted
Zigzagify a Matrix
J, 31 30 14 12 11 bytes
[:;<@|.`</.
Ych. Too big.
Takes a matrix as input.
Explanation
J has an advantage here. There's a command called oblique (...
- 11.3k
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.
...
- 209k
30
votes
Dig a border trench
Wolfram Language (Mathematica), 15 bytes
2#-#~Erosion~1&
Try it online!
Or (39 bytes):
...
- 21.4k
30
votes
Slash the matrix
MATL, 21 bytes
3XytPJ*-X*Xj~4&1ZIunq
The input is a matrix with 1 for \ and ...
- 104k
29
votes
Determinant of an Integer Matrix
Jelly, 15 bytes
LŒ!ðŒcIṠ;ị"Pð€S
Try it online!
How it works
...
- 49.5k
28
votes
I transpose the source code, you transpose the input!
Python 3 + numpy, 45 bytes
lambda\
a:a
ma= """
b. "
dT" "
a "
\ """
Try it online!
Thanks to @EriktheOutgolfer pointing out a bug of the previous version
...
- 1,751
26
votes
Construct the Identity Matrix
MATL, 2 bytes
Xy
A translation of my Octave answer.
Try it online.
A 4 byte version with no built-ins (thanks to Luis Mendo):
...
- 11.2k
24
votes
Calculate the inverse of a matrix
Octave, 57 bytes
A=input('');V=A'/trace(A*A');for i=1:1e4V=2*V-V*A*V;end
V
Try it online!
This is not particularly well golfed, but I wanted to advertise an ...
- 14.4k
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 ...
- 163k
22
votes
First spiral, then diagonal
R, 43 34 bytes
function(n)(8*n^3-3*n^2+4*n+3)%/%6
Try it online!
The OEIS page lists the following formula for a(n):
...
- 27.9k
21
votes
Accepted
20
votes
Construct the Identity Matrix
TI-BASIC, 2 bytes
identity(Ans
Fun fact: The shortest way to get a list {N,N} is ...
- 21.4k
20
votes
Accepted
Diamondize a Matrix
J, 6 bytes
<@|./.
This is an unnamed a monadic verb which takes a matrix and returns a list of antidiagonals:
...
- 196k
20
votes
Orthodiagonal steps
Octave, 24 bytes
dec2base([0:3,5:8],3)-49
Try it online!
I haven't seen this approach yet.
Creates a list of integers ...
- 46.1k
20
votes
Is the matrix centrosymmetric... and so is the code?
JavaScript (ES6), size 12 11 9
All versions return false for centrosymmetric or true for non-centrosymmetric.
1-dimensional array + length, size 9 (89 bytes)
Takes input in currying syntax ...
- 186k
19
votes
19
votes
Matrix with 1 to L(n), in all n columns
R, 40 38 bytes
function(l)outer(m<-1:max(l),l,"<=")*m
Try it online!
Explanation:
outer applies its third argument (...
- 27.9k
19
votes
Friar simulator
Grime, 20 bytes
n`.\1./\3.\4/.\2.voO
Try it online!
A very literal implementation of the spec:
n` make Grime count the ...
- 196k
19
votes
Accepted
Rebuild a rectangular array from a corner
Canvas, 1 byte
╬
Try it here!
Outputs as a multiline string
- 20.2k
19
votes
Find the inverse of a 3 by 3 matrix
MATL, 54 bytes
th3LZ)t,3:q&XdpswP]w-lw/GtY*tXdsGXdsUw-IXy*2/+GtXds*-*
Try it online!
Just to keep it interesting, doesn't use the inbuilt matrix division or ...
- 6,582
18
votes
Construct the Identity Matrix
APL, 5 bytes
∘.=⍨⍳
This is a monadic function train that accepts an integer on the right and returns the identity matrix.
Try it here
- 24.6k
18
votes
Construct the Identity Matrix
Julia, 9 3 bytes
eye
This is just a built-in function that accepts an integer n and returns an ...
- 24.6k
18
votes
Is the matrix centrosymmetric... and so is the code?
Jelly, score 2
⁼Ṛ
Ṛ⁼
Try it online!
Takes input as a flattened square matrix (vector of size \$n^2\$).
- 40.4k
18
votes
Make a Rectangle from a Triangle
Python 2, 59 bytes
n=input()
c=~n%2
while c<n:print`n%10`*n+`c%10`*c;n-=1;c+=1
Try it online!
Prints like:
...
- 144k
18
votes
Output a Latin Square
Python 2, 37 bytes
Outputs a flattened \$ n \times n \$ latin square.
lambda n:((range(n)*-~n)[1:]*n)[::~n]
Try it online!
- 22.2k
17
votes
16
votes
Construct the Identity Matrix
Python 2, 42 bytes
lambda n:zip(*[iter(([1]+[0]*n)*n)]*n)[:n]
An anonymous function, produces output like ...
- 144k
Only top scored, non community-wiki answers of a minimum length are eligible