Reconstruir uma matriz retangular a partir de um canto

30

Certa vez, tive uma bela matriz retangular. Era muito simétrico, mas infelizmente desmoronou e agora só tenho o canto superior esquerdo. Sua tarefa será reconstruir a matriz original.

Seu programa receberá uma matriz bidimensional de números inteiros. Para facilitar a análise, você pode assumir que todos estão entre 1 e 9. Sua tarefa é inverter as colunas da matriz, suas linhas e ambas, costurar os cantos resultantes e retornar a matriz resultante.

Você pode assumir que as dimensões da matriz serão pelo menos 1x1.

Casos de teste:

Input:
1 2 3
4 5 6

Output:
1 2 3 3 2 1
4 5 6 6 5 4
4 5 6 6 5 4
1 2 3 3 2 1

Input:
1

Output:
1 1
1 1

Input:
9
9
9

Output:
9 9
9 9
9 9
9 9
9 9
9 9

Isso é código-golfe , o menor número de bytes vence!

code-golf array-manipulation matrix

— Pavel
fonte

1

Aposto que o carvão pode fazer isso em menos de 10 anos

— FantaC

1

@tbfninja chat.stackexchange.com/transcript/message/43184083#43184083, mas talvez seja mais curto com um formato de entrada diferente.

— Pavel

@MagicOctopusUrn yes

— Pavel

2

@tfbninja ＷＳ⟦ι⟧‖Ｍ→↓talvez? 5 bytes para ler a entrada e 4 para refleti-la.

— 305 Neil

4

Estou 99% certo de que há uma lang que fazer isso com ╬(ou algum personagem similar) só não lembro qual: c

— Rod

Respostas:

1

Próton , 29 bytes

a=>[b+b[by-1]for b:a+a[by-1]]

Experimente online!

Existem algumas outras abordagens interessantes:

Próton , 29 bytes

a=>map(g,(g=x=>x+x[by-1])(a))

Experimente online!

Você pode definir a subfunção de espelho gin-line, porque Proton. Não é mais curto.

Próton , 36 bytes

(a=>[x[0]for x:zip(*(a+a[by-1]))])*2

Experimente online!

This should be (a=>zip(*(a+a[by-1])))*2 which is 24 bytes, but the zip function is completely broken. Basically, you mirror it and zip, and then do that twice (you can multiply a function by a positive integer to apply the function multiple times).

— HyperNeutrino
fonte

19

Canvas, 1 byte

╬

Outputs as a multiline string

— dzaima
fonte

2

Nice, @Rod called that one hah! Is this your language too Dzaima?

— Magic Octopus Urn

Damn... I should've remembered...

— totallyhuman

@MagicOctopusUrn Yeah, IIRC it's meant to basically be S.O.G.L. II: Electric Boogaloo?

— ASCII-only

12

Haskell, 25 24 bytes

r=(++)<*>reverse
r.map r

— nimi
fonte

5

Python 3, 38 bytes

lambda a:[b+b[::-1]for b in a+a[::-1]]

Takes a list of lists and returns a list of lists.

Explanation:

lambda a:                              # anonymous lambda function
                   for b in a+a[::-1]  # for each row in the array and the upside-down array
          b+b[::-1]                    # the row with its reverse appended
         [                           ] # return in a list

— pizzapants184
fonte

5

Husk, 7 6 bytes

Coincidentally, Erik had posted the exact same code in the Husk chatroom about a minute before I posted this.

‼oTS+↔

Pervious version, 7 bytes:

mS+↔S+↔

— Mr. Xcoder
fonte

5

Retina, 13 bytes

\%`$
$^$`
Vs`

Explanation

\%`$
$^$`

On each line (%), match the end of the line ($), and insert the reverse ($^) of the entire line ($`) and print the result with a trailing linefeed (\). This does the reflection along the vertical axis and prints the first half of the output.

Vs`

This just reverses the entire string, which is equivalent to a 180° degree rotation, or in our case (due to the horizontal symmetry) a reflection along the horizontal axis. This way this works is that V's (reverse) default regex is (?m:^.*$), which normally matches each line of the string. However, we activate the singleline option s, which makes . match linefeeds as well and therefore this default regex actually matches the entire string.

The result of this is printed automatically at the end of the program, giving us the second half of the output.

— Martin Ender
fonte

This doesn't look like any regex flavor I know of :P

— Pavel

@Pavel Because Retina isn't just regex. :)

— Erik the Outgolfer

@Pavel the only part of that code that is an actual regex is the $ on the first line. ;) I'll add an explanation later.

— Martin Ender

5

05AB1E, 2 bytes

∞∊

   # Input:Array of String | ['12','34']
---#-----------------------+------------------------------------------
∞  # Mirror horizontally.  | [12,34]       -> [1221,3443]
 ∊ # Mirror vertically.    | [1221,3443]   -> [1221\n3443\n3443\n1221]

Credit for Mr. Xcoder pointing out that arrays of string may count as 2D arrays and Pavel for confirming it.

— Magic Octopus Urn
fonte

... 2 bytes

— Mr. Xcoder

For ease of parsing, you may assume they are all between 1 and 9 – So I think this is valid. Awaiting Pavel's confirmation, I guess

— Mr. Xcoder

@Mr.Xcoder that was what I had initially, then the TIO 2D arrays as input was weird... so had to come up with that header stuff.

— Magic Octopus Urn

A string is an array of characters, so a list of strings is still a 2d array. @Mr.Xcoder's solution is valid.

— Pavel

Coolio, works for me.

— Magic Octopus Urn

3

Jelly, 5 bytes

m€0m0

— Erik the Outgolfer
fonte

Also 5 bytes: m0Z$⁺ (by Hyper Neutrino).

— Pavel

3

MATL, 5 bytes

,tPv!

Explanation:

(implicit input)
,               # do twice:
 t              # dup top of stack
 P              # flip vertically
 v              # vertically concatenate
 !              # transpose
(implicit output)

— Giuseppe
fonte

3

Octave, 33 29 bytes

Thanks to @Giuseppe for golfing four bytes!

@(A)[B=[A;flip(A)] fliplr(B)]

— Steadybox
fonte

29 bytes

— Giuseppe

3

JavaScript (Node.js), 62 55 49 46 bytes

A=>(j=x=>[...x,...[...x].reverse()])(A).map(j)

Because Array.prototype.reverse() reverses the array in place, I have to make a shallow copy somewhere first. A=>(j=x=>[...x,...x.reverse()])(A).map(j) does not work.

— Shieru Asakoto
fonte

3

J, 12 bytes

(,|.)@,.|."1

Explanation

         |."1 - reverse each row
       ,.     - and stitch them to the input
 (   )@       - and 
  ,|.         - append the rows in reversed order

— Galen Ivanov
fonte

3

awk, 88 bytes

{s="";for(i=NF;i>0;i--)s=" "$i s" "$i;a[FNR]=s;print s}END{for(i=NR;i>0;i--)print a[i]}

— mmuntag
fonte

3

Welcome to PPCG! Nice first answer :)

— HyperNeutrino

2

Triangularity, 31 bytes

...)...
..IEM..
.DRs+}.
DRs+...

Explanation

Removing the characters that make up for the padding, here is what the program does:

)IEMDRs+}DRs+ – Full program. Takes a matrix as a 2D list from STDIN.
)             – Push a 0 onto the stack.
 I            – Take the input at that index.
  E           – Evaluate it.
   M    }     – For each row...
    DR        – Duplicate and replace the second copy by its reverse.
      s+      – Swap and append.
         DR   – Duplicate the result and replace the second copy by its reverse.
           s+ – Swap and append.

— Mr. Xcoder
fonte

2

R, 57 bytes

function(m)rbind(N<-cbind(m,m[,ncol(m):1]),N[nrow(N):1,])

— Giuseppe
fonte

2

APL+WIN, 11 bytes

Prompts for a 2d array of integers.

m⍪⊖m←m,⌽m←⎕

— Graham
fonte

2

Stax, 5 bytes

:mm:m

Run and debug it online

:m means mirror, which is input.concat(reverse(input)). m, in this context means output each line after applying...

So, mirror the array of rows, and then mirror each row and output.

— recursive
fonte

2

Japt, 6 bytes

mê1 ê1

Explanation

           :Implicit input of 2D array
m          :Map
 ê1        :  Mirror sub array
    ê1     :Mirror main array

— Shaggy
fonte

2

Mathematica, 29 bytes

(g=#~Join~Reverse@#&)@*Map[g]

— totallyhuman
fonte

2

SOGL V0.12, 2 bytes

-1 byte thanks to dzaima.

╬ø

— totallyhuman
fonte

2

APL (Dyalog Classic), 7 bytes

⍪∘⊖⍨⊢,⌽

— ngn
fonte

2

Ruby, 35 bytes

->a{r=->b{b+b.reverse}
r[a].map &r}

A lambda accepting a 2D array and returning a 2D array. It's straightforward, but here's the ungolfed version anyway:

->a{
  r=->b{ b+b.reverse } # r is a lambda that returns the argument and its reverse
  r[a].map &r          # Add the array's reverse, then add each row's reverse
}

— benj2240
fonte

2

Java 8, 140 131 bytes

m->{String r="";for(int a=m.length,b=m[0].length,i=a+a,j;i-->0;r+="\n")for(j=b+b;j-->0;)r+=m[i<a?i:a+a+~i][j<b?j:b+b+~j];return r;}

Explanation:

m->{                      // Method with integer-matrix parameter and String return-type
  String r="";            //  Result-String, starting empty
  for(int a=m.length,     //  Amount of rows of the input-matrix
          b=m[0].length,  //  Amount of columns of the input-matrix
          i=a+a,j;        //  Index integers
      i-->0;              //  Loop over double the rows
      r+="\n")            //    After every iteration: append a new-line to the result
     for(j=b+b;j-->0;)    //   Inner loop over double the columns
       r+=                //    Append the result with:
          m[i<a?          //     If `i` is smaller than the amount of rows
             i            //      Use `i` as index in the input-matrix
            :             //     Else:
             a+a+~i]      //      Use `a+a+i-1` as index instead
           [j<b?          //     If `j` is smaller than the amount of columns
             j            //      Use `j` as index in the input-matrix
            :             //     Else:
             b+b+~j];     //      Use `b+b+j-1` as index instead
  return r;}              //  Return the result-String

— Kevin Cruijssen
fonte

2

J, 11 bytes

Anonymous tacit prefix function.

|:@(,|.)^:2

|: transpose

@(…) the result of:

, the argument followed by

|. its reverse

^:2 and all this done twice

— Adám
fonte

2

SNOBOL4 (CSNOBOL4), 119 113 bytes

	T =TABLE()
I	X =X + 1
	I =INPUT	:F(D)
	OUTPUT =T<X> =I REVERSE(I)	:(I)
D	X =X - 1
	OUTPUT =GT(X) T<X>	:S(D)
END

Takes input as strings on STDIN, without spaces. This only works because the digits are 1-9 and would fail otherwise.

— Giuseppe
fonte

I can see why people don't use this language anymore. This is so weird.

— Pavel

1

@Pavel SNOBOL is truly a terrible language to work with. this is a more modern C implementation of it which has additional builtin functions like REVERSE; the original only supported integer arithmetic as well, as far as I can tell.

— Giuseppe

2

C (gcc), 114 111 bytes

Saved three bytes thanks to Kevin Cruijssen; inverting the loops.

j,i;f(A,w,h)int*A;{for(i=h+h;i-->0;puts(""))for(j=w+w;j-->0;)printf("%d,",A[(i<h?i:h+h+~i)*w+(j<w?j:w+w+~j)]);}

C (gcc), 109 bytes (abusing ease of parsing)

Thanks to Kevin Cruijssen for suggesting to only allow one-digit input integers; saved two bytes.

j,i;f(A,w,h)int*A;{for(i=h+h;i-->0;puts(""))for(j=w+w;j-->0;)putchar(A[(i<h?i:h+h+~i)*w+(j<w?j:w+w+~j)]+48);}

— Jonathan Frech
fonte

You can save 3 bytes by inverting the loops. for(i=h+h;i-->0;puts(""))for(j=w+w;j-->0;)

— Kevin Cruijssen

Does not fulfill spec; prints the array, rather than returning it.

"For ease of parsing, you may assume they are all between 1 and 9.", so you can remove the comma in the printf("%d" for an additional -1 byte.

— Kevin Cruijssen

@Rogem I would say printing the array falls under accepted i/o.

— Jonathan Frech

1

@KevinCruijssen Thanks a lot; using the ease of parsing I managed to shave off another byte.

— Jonathan Frech

2

Charcoal, 5 bytes

θ‖Ｃ→↓

Thanks to ASCII-only for a better input format.

— Erik the Outgolfer
fonte

I wonder if this input format is valid, since I'm afraid Charcoal can't handle input otherwise. If it isn't, I'll happily delete this answer.

— Erik the Outgolfer

This is valid I/o.

— Pavel

@Pavel I just wondered because you had said that "Your program will receive a 2 dimensional array of integers", while a string is 1-dimensional (and no, the outer [] don't exactly make it 2D).

— Erik the Outgolfer

@ASCII-only Charcoal really needs a better I/O method...

— Neil

@Neil He didn't get pinged here, but I pinged him over TNB. :)

— Erik the Outgolfer

2

Add++, 30 bytes

D,f,@,bU€{r}B]{r}
D,r,@,dbR+

The footer simply transforms the nested array into the format in the question. Defines a function f, which expects a matrix (nested array) as an argument.

— caird coinheringaahing
fonte

1

Julia 0.6, 55 49 bytes

~i=i:-1:1
!x=[x x[:,~end];x[~end,:] x[~end,~end]]

~(i) is a function to create slice from i down to 1.
So ~end gives the slice end:-1:1

!(x) is the function to do the rebuilding of the array.

— Lyndon White
fonte

1

V, 12 bytes

yGæGPÎy$æ_|P

Explanation:

yG              " Yank every line
  æG            " Reverse the order of the lines
    P           " Paste what we yanked
     Î          " On every line:
      y$        "   Yank the whole line
        æ_      "   Reverse the whole line
          |     "   Move to the beginning of the line
           P    "   Paste what we yanked

— DJMcMayhem
fonte

Ao utilizar nosso site, você reconhece que leu e compreendeu nossa Política de Cookies e nossa Política de Privacidade.

Licensed under cc by-sa 3.0 with attribution required.