30
votes
Slash the matrix
MATL, 21 bytes
3XytPJ*-X*Xj~4&1ZIunq
The input is a matrix with 1 for \ and ...
- 107k
29
votes
Is there a single straight line in the matrix?
Python 2, 49 bytes
Takes as input a 2D binary matrix \$ a \$, and its size \$ n \$.
lambda a,n:sorted(map(sum,a+zip(*a)))[-2:]==[1,n]
Try it online!
There may be ...
- 23.4k
20
votes
Is it bipartite?
Wolfram Language (Mathematica), 26 25 bytes
Tr[#//.x_:>#.#.Clip@x]<1&
Try it online!
How it works
Given an adjacency matrix A, we find the fixed ...
- 5,305
18
votes
To find islands of 1 and 0 in matrix
J, 57 bytes
,&([:(0#@-.~~.@,)](*@[*[:>./((,-)#:i.3)|.!.0])^:_ i.@$)-.
Try it online!
This is one of those where the idea is incredibly simple (and I ...
- 34.1k
17
votes
To find islands of 1 and 0 in matrix
APL (Dyalog Unicode), 29 28 bytesSBCS
-1 thanks to @Adám
{≢∪∨.∧⍨⍣≡2>+/↑|∘.-⍨⍸⍵}¨⊂,~∘⊂
Try it online!
⊂,~∘⊂ the matrix and ...
- 15.6k
16
votes
ASCII texturing
APL (Dyalog Unicode), 20 12 bytesSBCS
-6 bytes through dzaima
Full program. Prompts stdin for:
texture as a list of strings
number of rows in shape matrix
number of columns in shape matrix
indices of ...
- 31.8k
16
votes
Just Enough Ones
J, 41 bytes
1#.*:=1#.2>[:>@~.@,[:+&,&.>/~i.@!<@A.=@i.
Try it online!
A different take on brute force, which handles up to n=6 on TIO.
Since the ...
- 34.1k
16
votes
Count my Pluses
MATL, 29 28 24 bytes
z2Y6ttX*,GbZ+5Mz=z]yytvs
Input is a binary matrix with 1 for '+' and <...
- 107k
15
votes
14
votes
Decode Faux Braille
Python 3, 181 179 171 167 161 159 bytes
Input by UTF-16 little-endian bytes without BOM. First decompose into columns using bit shifts, split by empty column, then hash them into a lookup table.
-2 ...
- 2,431
14
votes
Mutually Attacking Queens
Python 2, 105 bytes
lambda b:sum(b[i+d::d][:(8,7-i%8,i%8)[d%8%5]].find('1')*int(c)>0for i,c in enumerate(b)for d in[1,7,8,9])
Try it online!
Explanation
We ...
- 69.7k
14
votes
13
votes
Accepted
Where is that snake going?
Wolfram Language (Mathematica), 16+83=99 bytes
Library import statement (16 bytes):
<<Combinatorica`
Actual function body (83 bytes):
...
- 17.6k
13
votes
Is there a left-right connection?
MATLAB/Octave, 115 109 98* bytes
-6 bytes thanks to Luis Mendo
-7 bytes thanks to Luis Mendo
...
- 888
12
votes
11
votes
The Binary Square Diagonal Sequence
Husk, 15 14 bytes
zȯḋm←CtNCİ□ṁḋN
Try it online!
Continually prints the results as an infinite list.
Explanation
I wonder whether there's a better way to get ...
- 198k
11
votes
11
votes
11
votes
Trim that distracting background off!
MATL, 5 bytes
JYaZy
Try it online! Or verify all test cases.
Explanation
...
- 107k
11
votes
Calculate COVID spread
Jelly, 10 bytes
ŒJạ€ŒṪ§Ṃ€Ṁ
Try it online!
-2 bytes thanks to Sisyphus
Calculate the Manhattan differences from all 0s to all 1s, and the answer is the maximum of ...
- 42.8k
11
votes
Calculate COVID spread
Wolfram Language (Mathematica), 90 78 bytes
f=Length@FixedPointList[ListConvolve[CrossMatrix@1,#,{2,2},0,Times,Max]&,#]-2&
Try it online!
-12 bytes, ...
- 261
11
votes
Accepted
Calculate COVID spread
Stencil ≢, 2 bytes
×v
Try it online!
≢ tallies the number of necessary steps (including ...
- 31.8k
11
votes
Is there a single straight line in the matrix?
Ruby, 47 bytes
->m,n{m.uniq[1]?m-[[0]*n]==[[1]*n]:m[0].sum==1}
Try it online!
Explain please:
Split the two cases:
If m has at least 2 different rows, remove ...
- 23.4k
11
votes
Scribble Pad for Nerds
Charcoal, 9 bytes
ＦＡ✳ι##‖↘#
Try it online! Link is to verbose version of code. Explanation:
ＦＡ
Loop over the directions.
...
- 184k
10
votes
Change the rules of Life
MATL, 24 23 bytes
xx:"tt3Y6Z+1Gm<8M2Gmb*+
Inputs are:
Array with birth rule
Array with survival rule
Number of generations
Matrix with initial cell ...
- 107k
10
votes
Mutually Attacking Queens
JavaScript (ES7), 86 bytes
Takes input as an array of 64 integers with 254 for a queen and 0 for an empty square.
...
- 206k
10
votes
Dungeon Crawler
Clean (with Snappy), 800 785 670 644 bytes
460 402 bytes of code + 360 242-byte string literal
(escaped here and on TIO because it isn't valid UTF-8)
You can verify the length of the literal here.
<...
- 8,157
10
votes
Is there a single straight line in the matrix?
Factor + math.unicode, 59 bytes
[ [ concat Σ = ] keep dup flip [ all-equal? ] bi@ or and ]
Try it online!
Takes \$n\$ and a ...
- 27.9k
10
votes
Is there a single straight line in the matrix?
JavaScript (ES6), 46 bytes
Thanks to @PertinentDetail for a bug fix
Expects a multiline string with a trailing line feed. Returns a Boolean value.
...
- 206k
10
votes
Only top scored, non community-wiki answers of a minimum length are eligible