Hapus nol di depan dan di belakang

31

Diberikan daftar / larik kosong yang hanya berisi bilangan bulat non-negatif seperti ini:

[0, 0, 0, 8, 1, 4, 3, 5, 6, 4, 1, 2, 0, 0, 0, 0]

Keluarkan daftar dengan trailing dan nol terkemuka dihapus

Output untuk ini adalah:

[8, 1, 4, 3, 5, 6, 4, 1, 2]

Beberapa test case lainnya:

[0, 4, 1, 2, 0, 1, 2, 4, 0] > [4, 1, 2, 0, 1, 2, 4]
[0, 0, 0, 0, 0, 0] > nothing
[3, 4, 5, 0, 0] > [3, 4, 5]
[6] > [6]

Kode terpendek menang

Lamaro
sumber
Apakah bilangan bulat bukan negatif saja? Saya sarankan Anda mengklarifikasi itu atau menambahkan test case dengan nomor lain
Luis Mendo
1
Bisakah kita berasumsi bahwa setidaknya akan ada satu lead dan satu trailing 0?
DJMcMayhem
4
Apa yang bukan? Saya dapat memikirkan beberapa hal berbeda yang merupakan variasi pada ketiadaan di Perl 6. Nil ()/ [] slip()/ Empty Any {}beberapa dari mereka tidak terdefinisi, beberapa didefinisikan tetapi tunggal, beberapa yang masuk ke daftar lain sehingga mereka tidak menambah jumlah elemen. (Ada banyak variasi berbeda Anykarena ada kelas / jenis dan peran)
Brad Gilbert b2gills
7
Apakah ini suatu kebetulan bahwa tidak ada bilangan bulat di atas 10 atau dapatkah kita berasumsi bahwa semua angka akan menjadi satu digit?
A Simmons
1
Bisakah kita input / output daftar sebagai string yang dibatasi? Sebagai contoh: "0,4,1,2,0,1,2,4,0" => "4,1,2,0,1,2,4"EDIT: Baru perhatikan banyak bahasa sudah melakukan ini.
Mwr247

Jawaban:

25

Jelly , 2 byte

Kode:

t0

Penjelasan:

t   # Trim off...
 0  #  zero at both sides

Cobalah online!

Adnan
sumber
10
Ini bekerja? Astaga. Saya pikir jawaban MATL itu gila.
Skyl3r
4
wut y no don do dis jelly
Addison Crump
Tentu saja Jelly mengalahkan setiap pria di luar sana hampir setiap saat ...
Erik the Outgolfer
Apakah Jelly digunakan dalam bisnis yang sebenarnya?
Chromozorz
Kawan, saya harap tidak
Caleb Paul
10

JavaScript (ES6) 43

a=>(f=a=>a.reverse().filter(x=>a|=x))(f(a))

Kurang golf

a=>{
  f=a=>a.reverse().filter(x=>a|=x) // reverse and remove leading 0
  // leverage js cast rules: operator | cast operands to integer
  // an array casted to integer is 0 unless the array is made of
  // a single integer value (that is ok for me in this case)
  return f(f(a)) // apply 2 times
}

Uji

F=a=>(f=a=>a.reverse().filter(x=>a|=x))(f(a))

function test(){
  var l=(I.value.match(/\d+/g)||[]).map(x=>+x)
  O.textContent=F(l)
}

test()
#I { width:90%}
<input id=I oninput='test()' value='0 0 1 3 7 11 0 8 23 0 0 0'>
<pre id=O></pre>

edc65
sumber
1
Bagus. f=(a,r=f(a,a))=>r.reverse().filter(x=>a|=x)juga 43 byte.
Neil
6

CJam, 13 byte

l~{_{}#>W%}2*

Dengan memasukkan array.

Versi yang lebih panjang:

l~             Puts input on the stack and parse as array
  {       }    Code block
   _           Duplicate the first thing on the stack
    {}#        Finds the index of the first non-0 value in the array, puts it on the stack
       >       Slices the array from that index
        W%     Reverses the array
           2*  Does the code block twice in total
Angela Xu
sumber
Saya berharap saya bisa menggunakan fakta bahwa mengkonversi ke dan dari basis akan menghapus nol di depan, tetapi sepertinya terlalu panjang.
Buah Esolanging
5

Pyth, 4 byte

.sQ0

Demo:

llama@llama:~$ pyth -c .sQ0
[0, 0, 0, 1, 2, 0, 3, 4, 0, 0, 5, 0, 0, 0, 0]
[1, 2, 0, 3, 4, 0, 0, 5]

Dari Pyth'srev-doc.txt :

.s <seq> <any>
    Strip from A maximal prefix and suffix of A consisting of copies of B.
Gagang pintu
sumber
5

05AB1E , 4 byte

Kode:

0Û0Ü

Cobalah online!

Penjelasan:

0Û    # Trim off leading zeroes
  0Ü  # Trim off trailing zeroes

Menggunakan pengodean CP-1252.

Adnan
sumber
5

R, 43 byte

function(x)x[cummax(x)&rev(cummax(rev(x)))]

atau sebagai baca / tulis STDIN / STDOUT

x=scan();cat(x[cummax(x)&rev(cummax(rev(x)))])

Ini menemukan maksimum kumulatif dari string awal dan akhir (terbalik). The &Operator mengkonversi dua vektor ini untuk satu logis dari ukuran yang sama seperti x, (nol akan selalu dikonversi ke FALSEdan segala sesuatu yang lain untuk TRUE), cara ini memungkinkan subset dari xsesuai dengan kondisi terpenuhi.

David Arenburg
sumber
5

Haskell , 29 byte

t=f.f;f=reverse.dropWhile(<1)
Itai Bar-Natan
sumber
4

Mathematica 34 27 byte

#//.{0,a___}|{a___,0}:>{a}&

Ini berulang kali menerapkan aturan penggantian sampai tindakan tersebut gagal memberikan output baru. 7 byte disimpan berkat Alephalpha.

Aturan pertama menghapus nol di awal; aturan kedua menghapus nol di akhir array.

DavidC
sumber
3
#//.{0,a___}|{a___,0}:>{a}&
alephalpha
4

05AB1E, 4 byte

0Û0Ü

Pada dasarnya memangkas memimpin lalu membuntuti nol input, diberikan sebagai array.

Cobalah online!

Paul Picard
sumber
3

Perl, 19 + 1 = 20 byte

s/^(0 ?)+|( 0)+$//g

Membutuhkan -pbendera:

$ perl -pE's/^(0 )+|( 0)+$//g' <<< '0 0 0 1 2 3 4 5 6 0 0 0'
1 2 3 4 5 6
andlrc
sumber
@ MartinBüttner Saya kira hampir sama setelah menekan [Tambah Komentar], sekarang saya hanya perlu mencari tahu sekarang untuk membiarkan penurunan harga menyimpan baris baru saya di blok kode
andlrc
Melalui peretasan HTML yang jahat. ;)
Martin Ender
1
17 + 1 byte:s/^0 | 0$//&&redo
Kenney
@ Kenney Itu indah :-) Anda harus memposting itu sebagai jawaban!
andlrc
Terima kasih! Orisinal saya juga 19 + 1 byte tetapi kemudian saya melihat jawaban Anda yang memberi saya ide untuk mencukur 2 lagi, jadi milik Anda jika Anda menginginkannya. Btw, jawaban Anda sebenarnya 18 +1 jika Anda menjatuhkan ?seperti pada contoh - tetapi itu tidak akan mengurangi "0"..
Kenney
3

Jelly, 10 byte

Uo\U,o\PTị

Ini tidak menggunakan builtin.

Uo\U            Backward running logical OR
    ,           paired with
     o\         Forward running logical OR
       P        Product
        T       All indices of truthy elements
         ị      Index the input at those values.

Coba di sini .

lirtosiast
sumber
3

Perl, 38 byte

$\.=$_}{$\=~s/^(0\n)*|(0\n)*\n$//gs

Jalankan dengan perl -p, (3 byte ditambahkan untuk -p).

Menerima angka pada STDIN, satu per baris; memancarkan angka pada STDOUT, satu per baris, sebagaimana seharusnya utilitas unix yang berperilaku baik.

Hanya memperlakukan angka yang diwakili dengan tepat oleh '0' sebagai nol; akan mungkin untuk mendukung representasi lain dengan beberapa byte lagi di regex.

Versi lebih lama, masih harus dijalankan dengan -p:

    # append entire line to output record separator
    $\.=$_
}{
    # replace leading and trailng zeroes in output record separator
    $\ =~ s/^(0\n)*|(0\n)*\n$//gs
    # output record separator will be implicitly printed

Versi yang diperluas, menunjukkan interaksi dengan flag -p:

# implicit while loop added by -p
while (<>) {
    # append line to output record separator
    $\.=$_
}{ # escape the implicit while loop
    # replace leading and traling 
    $\=~s/^(0\n)*|(0\n)*\n$//gs
    # print by default prints $_ followed by
    # the output record separator $\ which contains our answer
    ;print # implicit print added by -p
} # implicit closing brace added by -p
David Morris
sumber
Dengan asumsi Anda menjalankan perl -E, -pflag biasanya hanya dihitung sebagai satu byte, karena hanya ada satu byte tambahan yang berbeda antara itu dan perl -pE.
Chris
3

Elixir, 77 byte

import Enum
z=fn x->x==0 end
reverse(drop_while(reverse(drop_while(l,z)),z))

l adalah array.

Edit: wah! salin / pasta gagal. tentu saja kita harus mengimpor Enum, yang meningkatkan jumlah byte sebanyak 12 (atau menggunakan Enum.function_name, yang akan membuatnya lebih lama).

srecnig
sumber
3

Vitsy, 13 byte

Vitsy perlahan menjadi lebih baik ... (Aku datang untukmu Jelly. ಠ_ಠ)

1mr1m
D)[X1m]

Ini keluar dengan array di stack. Agar mudah dibaca, TryItOnline! tautan yang saya berikan di bawah penjelasan akan menampilkan daftar yang diformat.

Penjelasan:

1mr1m
1m      Do the second line of code.
  r     Reverse the stack.
   1m   I'ma let you figure this one out. ;)

D)[X1m]
D       Duplicate the top item of the stack.
 )[   ] If the top item of the stack is zero, do the stuff in brackets.
   X    Remove the top item of the stack.
    1m  Execute the second line of code.

Perhatikan bahwa ini akan melempar StackOverflowException untuk input besar yang tidak masuk akal.

TryItOnline!

Addison Crump
sumber
2
Vitsy akan mendapatkan Jelly suatu hari nanti.
Conor O'Brien
Tambahkan pencocokan braket otomatis pada EOL / EOF
Cyoce
3

R, 39 byte

function(x)x[min(i<-which(x>0)):max(i)]

Empat byte lebih pendek dari jawaban R David Arenburg ini . Implementasi ini menemukan indeks pertama dan terakhir dalam array yang lebih besar dari nol, dan mengembalikan semuanya dalam array di antara kedua indeks tersebut.

rturnbull
sumber
3

MATL , 9 byte

2:"PtYsg)

Cobalah online!

Penjelasan

2:"     % For loop (do the following twice)
  P     %   Flip array. Implicitly asks for input the first time
  t     %   Duplicate
  Ys    %   Cumulative sum
  g     %   Convert to logical index
  )     %   Apply index
        % Implicitly end for
        % Implicitly display stack contents
Luis Mendo
sumber
2

Dyalog APL, 15 bytes

{⌽⍵↓⍨+/0=+\⍵}⍣2

               ⍣2     Apply this function twice:
{             }       Monadic function:
           +\⍵        Calculate the running sum.
       +/0=           Compare to zero and sum. Number of leading zeroes.
   ⍵↓⍨               Drop the first that many elements from the array.
 ⌽                   Reverse the result.

Try it here.

lirtosiast
sumber
How about {⌽⍵/⍨×+\⍵}⍣2?
lstefano
2

Ruby, 49 44 bytes

->a{eval ?a+'.drop_while{|i|i<1}.reverse'*2}

Thanks to manatwork for chopping off 5 bytes with a completely different method!

This just drops the first element of the array while it's 0, reverses the array, repeats, and finally reverses the array to return it to the proper order.

Doorknob
sumber
Ouch. Now even a .drop_while() based solution would be shorter (if using 2 functions): f=->a{a.drop_while{|i|i<1}.reverse};->a{f[f[a]]}
manatwork
Doh. No need for 2 functions, just some eval ugliness: ->a{eval ?a+'.drop_while{|i|i<1}.reverse'*2}.
manatwork
@manatwork Not sure why I didn't think of <1, anyway. Thanks!
Doorknob
2

Vim 16 Keystrokes

i<input><esc>?[1-9]<enter>lD0d/<up><enter>

The input is to be typed by the user between i and esc, and does not count as a keystroke. This assumes that there will be at least one leading and one trailing zero. If that is not a valid assumption, we can use this slightly longer version: (18 Keystrokes)

i <input> <esc>?[1-9]<enter>lD0d/<up><enter>
DJMcMayhem
sumber
1
I don't think you need to include code to allow the user to input the numbers (i and <esc>). In vim golf the golfer starts with the input already in a file loaded the buffer and the cursor in the top left corner, but the user also has to save and exit (ZZ is usually the fastest way). Then you could do something like d[1-9]<enter>$NlDZZ (13 keystrokes). Note N/n instead of /<up><enter>
daniero
2

ES6, 51 bytes

f=a=>a.map(x=>x?t=++i:f<i++||++f,f=i=0)&&a.slice(f,t)

t is set to the index after the last non-zero value, while f is incremented as long as only zeros have been seen so far.

Neil
sumber
2

Perl 6, 23 bytes

{.[.grep(?*):k.minmax]}
{.[minmax .grep(?*):k]}

Usage:

# replace the built-in trim subroutine
# with this one in the current lexical scope
my &trim = {.[.grep(?*):k.minmax]}

say trim [0, 0, 0, 8, 1, 4, 3, 5, 6, 4, 1, 2, 0, 0, 0, 0];
# (8 1 4 3 5 6 4 1 2)
say trim [0, 4, 1, 2, 0, 1, 2, 4, 0];
# (4 1 2 0 1 2 4)
say trim [0, 0, 0, 0, 0, 0];
# ()
say trim [3, 4, 5, 0, 0];
# (3 4 5)
say trim [6];
# (6)
Brad Gilbert b2gills
sumber
2

Retina, 11 bytes

+`^0 ?| 0$
<empty>

Quite simple. Recursively replaces zeroes at beginning and end of line.

Try it online!

Mama Fun Roll
sumber
2

JavaScript (ES6), 47 bytes

a=>a.join(a="").replace(/(^0+|0+$)/g,a).split(a)

Where a is the array.

user2428118
sumber
4
I think you need to make an anonymous function to take input: a=>a.join(a="")....
andlrc
2
This only handles integers properly when they're a single digit
aross
@dev-null Done.
user2428118
Still returning wrong for multi-digit integers. [14] will return [1, 4].
Mwr247
Actually, I was (and am) still awaiting a reply to this comment. Anyway, I unfortunately don't see a way to do handle multi-digit integers using the same technique I've used for my answer and I don't think I'll be able to beat this answer anyway. I may try when I have the time, though.
user2428118
2

Python, 84 characters

def t(A):
 if set(A)<={0}:return[]
 for i in(0,-1):
  while A[i]==0:del A[i]
 return A
pafcjo
sumber
You can do for i in-1,0:
mbomb007
I count 86 bytes.
Erik the Outgolfer
2

JavaScript (ES6), 34 bytes

a=>a.replace(/^(0 ?)*|( 0)*$/g,'')

Input and output are in the form of a space-delimited list, such as "0 4 1 2 0 1 2 4 0".

Mwr247
sumber
2

Javascript (ES6) 40 bytes

a=>/^(0,)*(.*?)(,0)*$/.exec(a.join())[2]
Shaun H
sumber
2

PHP, 56 54 52 bytes

Uses Windows-1252 encoding

String based solution

<?=preg_replace(~ÜÒ×ßÏÖÔƒ×ßÏÖÔÛÜ,"",join($argv,~ß));

Run like this:

echo '<?=preg_replace(~ÜÒ×ßÏÖÔƒ×ßÏÖÔÛÜ,"",join($argv,~ß));' | php -- 0 0 123 234 0 500 0 0 2>/dev/null;echo

If your terminal is set to UTF-8, this is the same:

echo '<?=preg_replace("#-( 0)+|( 0)+$#","",join($argv," "));' | php -- 0 0 123 234 0 500 0 0 2>/dev/null;echo

Tweaks

  • Saved 2 bytes by negating strings and dropping string delimiters
  • Saved 2 bytes by using short print tag
aross
sumber
1
Can you please provide an ASCII solution. Nobody can read this!
Titus
1
@Titus Sure. However, plenty of unreadable esolangs out there.... it's not like my answer doesn't feel right at home.
aross
An array as first parameter of join?
Jörg Hülsermann
1
@JörgHülsermann Yup. It's documented the other way around but it accepts both.
aross
You are right I have not realize it
Jörg Hülsermann
2

Python 2, 69 67 bytes

def f(a):
 for i in(0,-1):
  while a and a[i]==0:a.pop(i)
 return a
SumnerHayes
sumber
You can remove the space before your tuple in the second line.
Zach Gates
You can do for i in-1,0:
mbomb007
Also, you might want to recount your bytes. I count 67 as is. You can also replace [space][space]while with [tab]while. And ==0 can be <1. mothereff.in/…
mbomb007
I count 67 bytes.
Erik the Outgolfer
1

PowerShell, 49 bytes

($args[0]-join',').trim(',0').trim('0,')-split','

Takes input $args[0] and -joins them together with commas to form a string. We then use the .Trim() function called twice to remove first the trailing and then the leading zeros and commas. We then -split the string on commas back into an array.


Alternate version, without using conversion
PowerShell, 81 bytes

function f{param($a)$a=$a|%{if($_-or$b){$b=1;$_}};$a[$a.Count..0]}
f(f($args[0]))

Since PowerShell doesn't have a function to trim arrays, we define a new function f that will do half of this for us. The function takes $a as input, then loops through each item with a foreach loop |%{...}. Each iteration, we check a conditional for $_ -or $b. Since non-zero integers are truthy, but $null is falsey (and $b, being not previously defined, starts as $null), this will only evaluate to $true once we hit our first non-zero element in the array. We then set $b=1 and add the current value $_ onto the pipeline. That will then continue through to the end of the input array, with zeros in the middle and the end getting added onto the output, since we've set $b truthy.

We encapsulate and store the results of the loop all back into $a. Then, we index $a in reverse order (i.e., reversing the array), which is left on the pipeline and thus is the function's return value.

We call the function twice on the $args[0] input to the program in order to "trim" from the front, then the front again (which is the back, since we reversed). The order is preserved since we're reversing twice.

This version plays a little loose with the rules for an input array of all zeros, but since ignoring STDERR is accepted practice, the program will spit out two (verbose) Cannot index into a null array errors to (PowerShell's equivalent of) STDERR and then output nothing.

AdmBorkBork
sumber