Sort band names

Question

Challenge description

You have a music library with many tracks recorded by many bands, each of which has a name, like Queen, Aerosmith, Sunny Day Real Estate, The Strokes . When an audio player displays your library alphabetically by band name, it usually skips the The part, as many band names start with The, making it easier to navigate through your media collection. In this challenge, given a list (array) of strings, you need to sort it that way (that is, omitting the The word at the beginning of the name). You can either write a method or a full working program.

Sample inputs / outputs

[Queen, Aerosmith, Sunny Day Real Estate, The Strokes] -> [Aerosmith, Queen, The Strokes, Sunny Day Real Estate]
[The Ramones, The Cure, The Pixies, The Roots, The Animals, Enrique Iglesias] -> [The Animals, The Cure, Enrique Iglesias, The Pixies, The Ramones, The Roots]
[The The, The They, Thermodynamics] -> [The The, Thermodynamics, The They]

Notes / Edge cases

• Sorting lexicographically is case insensitive, so The Police, The police and the police are all equivalent,

• Your algorithm should only omit the first the word, so bands named The The or The The Band are sorted normally by the second the,

• A band named The (a three letter word) is sorted normally (no skipping),

• Order of two bands having the same name, one of which starts with the (like The Police and Police) is undefined,

• You can assume that if a band's name consists of more than one word, they are separated by a single space character. You don't need to handle leading or trailing whitespaces,

• All input strings match [A-Za-z0-9 ]*, that is they will consist only of lower- and uppercase letters of English alphabet, digits and space characters,

• Remember that this is a code-golf challenge, so make your code as short as possible!

Answer 1

Python, 56 62 64 bytes

lambda b:sorted(b,key=lambda x:(x,x[4:])[x.lower()[:4]=='the '])

Try it

Thanks to @Chris H for pointing out that lstrip() was not handling The The correctly, since the strip was blasting all matching characters and sorting it as a blank string, and @manatwork for finding the flaw in using replace(). The new version should work.

Old version:

lambda b:sorted(b,key=lambda x:x.lower().lstrip('the '))

Answer 2

V, 32 28 bytes

ç^The /dwA_
:sort
ç_/$xIThe 

Try it online!

Note to self: Make an abbreviation for :sort so that I don't need 6 whole bytes for a single command!

Explanation:

ç^The /     "On every line starting with 'The ',
       dw   "Delete a word
         A_ "And (A)ppend an underscore '_'

:sort       "Sort all lines alphabetically

ç_/         "On every line containing an underscore,
   $x       "Delete the last character
     IThe   "And prepened 'The '

Answer 3

Retina, 34 bytes

The trailing linefeed is significant.

%`^
$';
T`L`l`.+;
m`^the 

O`
.+;

I/O is one band per line.

Try it online!

Explanation

%`^
$';

Duplicate each line, using ; as a separator.

T`L`l`.+;

Turn everything in front of a ; to lower case.

m`^the 

Remove any thes that appear at the beginning of a line.

O`

Sort the lines.

.+;

Remove the beginnings of the lines which we used for sorting.

Answer 4

Pyke, 16 bytes

.#l1D"the ".^4*>

Try it here!

.#                - sort_by(V, input)
  l1              -  i = i.lower()
      "the ".^    -   i.startswith("the ")
              I   -  if ^:
               4> -   i[4:]

Answer 5

Perl, 52 bytes

-13 byte thanks to @manatwork
-1 byte thanks to @msh210

sub f{lc pop=~s/^the //ri}print sort{f($a)cmp f$b}<>

One band per line as input, and so is the output.

The implementation is quite straight forward : the program prints the list of bands, sorted with the help of a custom function (f) which returns the lower case band name without the eventual leading the.

Answer 6

Python, 66 72 69 bytes

lambda x:sorted(x,key=lambda a:a[4*(a.lower()[:4]=='the '):].lower())

Uses Python's sorted method with the key keyword argument to sort by the name minus "The". This is a lambda; to call it, give it a name by putting f= in front.

Now with extra case insensitivity!

Answer 7

PowerShell v2+, 33 32 29 bytes

$args|sort{$_-replace'^the '}

Saved 3 bytes thanks to @MathiasRJessen

Input is via command-line arguments. Sorts the original names based on the results of the script block {...} that performs a regex -replace to strip out the leading (case-insensitive) "the ".

Examples

PS C:\Tools\Scripts\golfing> .\sort-band-names.ps1 'the Ramones' 'The cure' 'The Pixies' 'The Roots' 'the Animals' 'Enrique Iglesias'
the Animals
The cure
Enrique Iglesias
The Pixies
the Ramones
The Roots

PS C:\Tools\Scripts\golfing> .\sort-band-names.ps1 'The The' 'The They' 'Thermodynamics'
The The
Thermodynamics
The They

PS C:\Tools\Scripts\golfing> .\sort-band-names.ps1 'THE STOOGES' 'The Strokes' 'The The' 'the they' 'the band' 'STP'
the band
THE STOOGES
STP
The Strokes
The The
the they

Answer 8

JavaScript/ECMAScript 6 93 70 bytes

70 Thanks to Neil and Downgoat for advice

B=>B.sort((a,b)=>R(a).localeCompare(R(b)),R=s=>s.replace(/^the /i,''))

Readable Version for the 70-byte variant

let sortBandNames = (bandNames) => {
    let stripThe = (name) => name.replace(/^the /i, '');
    let compareFunc = (a, b) => stripThe(a).localeCompare(stripThe(b));
    return bandNames.sort(compareFunc)
};

93

f=B=>{R=s=>s.toLowerCase().replace(/the /,'');return B.sort((a,b)=>R(a).localeCompare(R(b)))}

Readable Version for the 93-byte variant

let sortBandNames = (bandNames) => {
    let stripThe = (name) => name.toLowerCase().replace(/the /, '');
    let compareFunc = (a, b) => stripThe(a).localeCompare(stripThe(b));
    return bandNames.sort(compareFunc)
};

Answer 9

Ruby, 42 bytes

->a{a.sort_by{|s|s.upcase.sub /^THE /,''}}

Try it online!

Answer 10

Perl 6, 26 bytes

*.sort({fc S:i/^'the '//})

Explanation:

# ｢*｣ is the input to this Whatever lambda
*.sort(

  # sort based on the return value of this Block lambda
  {
    fc # foldcase the following

    # string replace but not in-place
    S
      :ignorecase
      /
        # at the start of the string
        ^

        # match ｢the ｣
        'the '

      # replace with nothing
      //
  }
)

Test:

use v6.c;
use Test;

my @tests = (
  « Queen Aerosmith 'Sunny Day Real Estate' 'The Strokes' »
    => « Aerosmith Queen 'The Strokes' 'Sunny Day Real Estate' »,
  « 'The Ramones' 'The Cure' 'The Pixies' 'The Roots' 'The Animals' 'Enrique Iglesias' »
    => « 'The Animals' 'The Cure' 'Enrique Iglesias' 'The Pixies' 'The Ramones' 'The Roots' »,
  « 'The The' 'The They' Thermodynamics »
    => « 'The The' Thermodynamics 'The They' »,
);

# give it a lexical name for clarity
my &band-sort = *.sort({fc S:i/^'the '//});

plan +@tests;

for @tests -> ( :key(@input), :value(@expected) ) {
  is-deeply band-sort(@input), @expected, @expected.perl;
}

1..3
ok 1 - ("Aerosmith", "Queen", "The Strokes", "Sunny Day Real Estate")
ok 2 - ("The Animals", "The Cure", "Enrique Iglesias", "The Pixies", "The Ramones", "The Roots")
ok 3 - ("The The", "Thermodynamics", "The They")

Answer 11

Java 8, 178 bytes

void q(String[]s){java.util.Arrays.sort(s,(a,b)->(a.toLowerCase().startsWith("the ")?a.substring(4):a).compareToIgnoreCase(b.toLowerCase().startsWith("the ")?b.substring(4):b));}

Ungolfed version:

void sort(String[] bands) {
    java.util.Arrays.sort(bands, (a, b) -> 
        (a.toLowerCase().startsWith("the ") ? a.substring(4) : a).compareToIgnoreCase(
            b.toLowerCase().startsWith("the ") ? b.substring(4) : b
        )
    );
}

Call as such:

public static void main(String[] args) {
    String[] bands = {"The Strokes", "Queen", "AC/DC", "The Band", "Cage the Elephant", "cage the elephant"};
    sort(bands); // or q(bands) in the golfed version
    System.out.println(java.util.Arrays.toString(bands));
}

Answer 12

Vim, 18 bytes

Well now that I realized this is possible, I'm kinda embarrassed by my 26 byte V answer, especially since V is supposed to be shorter than vim. But this is pretty much a builtin.

:sor i/\(The \)*/<CR>

Explanation (straight from vim help):

                            *:sor* *:sort*
:[range]sor[t][!] [b][f][i][n][o][r][u][x] [/{pattern}/]
            Sort lines in [range].  When no range is given all
            lines are sorted.

            With [i] case is ignored.

            When /{pattern}/ is specified and there is no [r] flag
            the text matched with {pattern} is skipped, so that
            you sort on what comes after the match.
            Instead of the slash any non-letter can be used.

Answer 13

C, 216 212 135 + 5 (qsort) = 221 217 140 bytes

M(void*a,void*b){char*A,*B;A=*(char**)a;B=*(char**)b;A=strcasestr(A,"The ")?A+4:A;B=strcasestr(B,"The ")?B+4:B;return strcasecmp(A,B);}

Well, I finally got around to finishing this in C. Golfing tips are very much appreciated.

In this submission, M is the comparison function to be supplied to qsort. Therefore, to invoke this, you must use qsort in the format qsort(argv++,argc--,8,M) where argv contains the command-line arguments and argc is the number of arguments provided.

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Answer 14

q/kdb+, 36 33 bytes

Solution:

{x(<)@[x;(&)x like"[Tt]he *";4_]}

Example:

q){x(<)@[x;(&)x like"[Tt]he *";4_]}("Queen";"Aerosmith";"Sunny Day Real Estate";"The Strokes";"the Eagles")
"Aerosmith"
"the Eagles"
"Queen"
"The Strokes"
"Sunny Day Real Estate"

Explanation:

Strip out any "[Tt]he " from each input string, sort this list, then sort the original list based on the indexing of the sorted list.

{x iasc @[x;where x like "[Tt]he *";4_]} / ungolfed solution
{                                      } / lambda function
        @[x;                       ;  ]  / apply function to x at indices
                                    4_   / 4 drop, remove first 4 items
            where x like "[Tt]he *"      / where the input matches 'The ...' or 'the ...'
   iasc                                  / returns sorted indices
 x                                       / index into original list at these indices

Answer 15

05AB1E, 27 bytes (non-competing)

vyð¡RD¤…TheQsgα£Rðý})‚øí{ø¤

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Explanation

vyð¡RD¤…TheQsgα£Rðý})‚øí{ø¤   Argument l
v                 }           For each y in l, do:
 yð¡                            Split y on space
    RD                          Reverse and duplicate
      ¤…TheQ                    Last element equals "The" (true = 1, false = 0)
            sgα                 Absolute difference with length of array
               £                Get elements from index 0 to calculated difference
                R               Reverse
                 ðý             Join on space
                    )‚øí      Pair each element with original
                        {ø¤   Sort and get the original band name

Answer 16

Groovy, 34 bytes

{it.sort{it.toLowerCase()-'the '}}

41% my answer is .toLowerCase(), kill me now.

---

Output

When running...

({it.sort{it.toLowerCase()-'the '}})(['The ramones','The Cure','The Pixies','The Roots','The Animals','Enrique Iglesias'])

The result is...

[The Animals, The Cure, Enrique Iglesias, The Pixies, The ramones, The Roots]

With no debug or error output.

Answer 17

Japt, 11 10 bytes

ñ_v r`^e 

Try it

Answer 18

Nim, 96 bytes

import algorithm,strutils,future
x=>x.sortedByIt toLower it[4*int(it.toLower[0..3]=="the ")..^0]

^{Those imports take up so many bytes :|}

A translation of my Python answer.

This is an anonymous procedure; to use it, it must be passed into a testing procedure. Here's a full program you can use for testing:

import algorithm,strutils,future
proc test(x: seq[string] -> seq[string]) =
 echo x(@["The The", "The They", "Thermodynamics"]) # Substitute your input here
test(x=>x.sortedByIt toLower it[4*int(it.toLower[0..3]=="the ")..^0])

Answer 19

MATL, 16 bytes

tk'^the '[]YX2$S

Input format is (each line corresponds to a test case)

{'Queen', 'Aerosmith', 'Sunny Day Real Estate', 'The Strokes'} 
{'The Ramones', 'The Cure', 'The Pixies', 'The Roots', 'The Animals', 'Enrique Iglesias'}
{'The The', 'The They', 'Thermodynamics'}

Try it online!

Explanation

t        % Implicitly input cell array of strings. Push another copy
k        % Convert to lowercase
'^the '  % String to be used as regex pattern: matches initial 'the '
[]       % Empty array
YX       % Regex replacement: replace initial 'the ' in each string by empty array
2$S      % Sort input according to the modified cell array. Implicitly display

Answer 20

Haskell, 84 bytes

import Data.List
p(t:'h':'e':' ':s)|elem t"Tt"=s
p s=s
sortBy(\a b->p a`compare`p b)

Call with

sortBy(\a b->p a`compare`p b)["The The", "The They", "Thermodynamics"]

Testcase:

let s = sortBy(\a b->p a`compare`p b)
and[s["Queen", "Aerosmith", "Sunny Day Real Estate", "The Strokes"]==["Aerosmith", "Queen", "The Strokes", "Sunny Day Real Estate"],s["The Ramones", "The Cure", "The Pixies", "The Roots", "The Animals", "Enrique Iglesias"]==["The Animals", "The Cure", "Enrique Iglesias", "The Pixies", "The Ramones", "The Roots"],s["The The", "The They", "Thermodynamics"]==["The The", "Thermodynamics", "The They"]]

Answer 21

C#, 139 Bytes

using System.Linq;System.Collections.IEnumerable S(string[] l)=> l.OrderBy(b=>(b.ToLower().StartsWith("the ")?b.Substring(4):b).ToLower());

Try online!

Without counting the usings the answer would be 102 bytes.

Answer 22

BASH, 64 Bytes

sed 's/^the / /;s/^The /    /'|sort -fb|sed 's/^ /the /;s/^ /The /'

Input: stdin, one band per line. Output: stdout

Note: The second replacements (s/^The/ / and s/^ /The /) use the tab character, so they don't always copy/paste correctly.

Answer 23

Bash + coreutils, 44 bytes

sed '/^the /I!s,^,@ ,'|sort -dk2|sed s,@\ ,,

Explanation: the input and output format is one band per line

sed '/^the /I!s,^,@ ,'   # prepend '@ ' to each line not starting with 'the ', case
                         #insensitive. This adds a temporary field needed by sort.
sort -dk2                # sort in ascending dictionary order by 2nd field onward
sed s,@\ ,,              # remove the temporary field

Test run (using a here-document with EOF as the end marker):

./sort_bands.sh << EOF
> Queen
> Aerosmith
> Sunny Day Real Estate
> The Strokes
> EOF

Output:

Aerosmith
Queen
The Strokes
Sunny Day Real Estate

Answer 24

Java 176 158 bytes

public String[]sort(String[]names){
  for(int i=-1;++i<names.length;)
    if(names[i].startsWith("(The |the )"))
      names[i]=names[i].substring(4);
  return Arrays.sort(names,String.CASE_INSENSITIVE_ORDER);
  }

Main Function

public static void main(String[]args){
  Scanner s = new Scanner(System.in);
  List<String> list= new ArrayList<>();
  while(!(String h = s.nextLine).equalsIgnoreCase("~")){
    list.add(h);
  }
System.out.println(sort(list.toArray(newString[0]))

); }

Golfed sort function:

String[]s(String[]n){for(int i=-1;++i<n.length;)if(n[i].startsWith("(The |the )"))n[i]=n[i].substring(4);return Arrays.sort(n,String.CASE_INSENSITIVE_ORDER);}

Thanks to @raznagul for saving 18 bytes