Determine if a string is collapsible: Difference between revisions

{{Template:Strings}}

<br><br>

 

=={{header|8080 Assembly}}==

 

puts: equ 9

org 100h

db 'and they think it',39,'s hell. $'

str5: db ' '

 

{{out}}

</pre>

 

 

=={{header|Ada}}==

procedure Test_Collapsible is

procedure Collapse (S : in String) is

Collapse (" --- Harry S Truman ");

end Test_Collapsible;

 

{{out}}

 

=={{header|ALGOL 68}}==

# returns a collapsed version of s #

# i.e. s with adjacent duplicate characters removed #

OD

END

{{out}}

<pre>

{{works with|Dyalog APL}}

 

⍝ Collapse a string

collapse←{(1,¯1↓⍵≠1⌽⍵)/⍵}

⍝ Collapse each string and display it as specified

↑collapse display¨ strs

 

{{out}}

17 ««« - Hary S Truman »»»

</pre>

 

=={{header|AutoHotkey}}==

for i, ch in StrSplit(str){

if (ch <> prev)

}

return "original string:`t" StrLen(str) " characters`t«««" str "»»»`nresultant string:`t" StrLen(res) " characters`t«««" res "»»»"

, """If I were two-faced, would I be wearing this one?"" --- Abraham Lincoln "

, "..1111111111111111111111111111111111111111111111111111111111111117777888"

for i, v in data

MsgBox % := collapsible_string(v)

Outputs:<pre>-----------------------------------------

original string: 0 characters «««»»»

resultant string: 17 characters ««« - Hary S Truman »»»

-----------------------------------------</pre>

=={{header|AWK}}==

# syntax: GAWK -f DETERMINE_IF_A_STRING_IS_COLLAPSIBLE.AWK

BEGIN {

printf("new: %2d <<<%s>>>\n\n",length(new_str),new_str)

}

{{out}}

<pre>

 

=={{header|BaCon}}==

DATA "\"If I were two-faced, would I be wearing this one?\" --- Abraham Lincoln "

DATA "..1111111111111111111111111111111111111111111111111111111111111117777888"

NEXT

PRINT ">>> - length: ", found

{{out}}

<pre><<<>>> - length: 0

=={{header|BASIC}}==

 

20 FOR A% = 1 TO N%

30 READ I$: GOSUB 100

430 DATA "..1111111111111111111111111111111111111111111111111111111111111117777888"

440 DATA "I never give 'em hell, I just tell the truth, and they think it's hell. "

 

{{out}}

 

=={{header|BCPL}}==

 

// Collapse a string

show("I never give 'em hell, I just tell the truth, and they think it's hell. ")

show(" --- Harry S Truman ")

{{out}}

<pre>0: <<<>>>

72: <<< --- Harry S Truman >>>

17: <<< - Hary S Truman >>></pre>

=={{header|Bracmat}}==

= previous

. str

$ "I never give 'em hell, I just tell the truth, and they think it's hell. "

& testcolapse

'''Output'''

<pre>«««»»» 0

Identical implementation as in [[Determine_if_a_string_is_squeezable]], as both tasks are very similar. The Lincoln quote contains backslashes to accommodate the double quotes via the command line. strcmpi is not part of the C Standard Library, thus comment out the definition in the code if testing on a system where it is already included.

 

#include<string.h>

#include<stdlib.h>

return 0;

}

Output :

<pre>

</pre>

 

using static System.Linq.Enumerable;

 

static string Collapse(string s) => string.IsNullOrEmpty(s) ? "" :

s[0] + new string(Range(1, s.Length - 1).Where(i => s[i] != s[i - 1]).Select(i => s[i]).ToArray());

{{out}}

<pre>

=={{header|C++}}==

The solution is a straightforward application of the standard library function "unique".

#include <iostream>

#include <algorithm>

test(" --- Harry S Truman ");

return 0;

 

{{out}}

 

=={{header|Clojure}}==

(defn collapse [s]

(let [runs (partition-by identity s)]

(str (format "Input: <<<%s>>> (len %d)\n" s (count s))

(format "becomes: <<<%s>>> (len %d)\n" out (count out)))))

 

{{out}}

becomes: <<< - Hary S Truman >>> (len 17)

</pre>

 

=={{header|Cowgol}}==

include "strings.coh";

 

show(strings[i]);

i := i + 1;

 

{{out}}

 

=={{header|D}}==

 

void collapsible(string s) {

collapsible(`I never give 'em hell, I just tell the truth, and they think it's hell. `);

collapsible(` --- Harry S Truman `);

{{out}}

<pre>old: <<<>>>, length = 0

{{libheader| System.SysUtils}}

{{Trans|D}}

program Determine_if_a_string_is_collapsible;

 

collapsible(' --- Harry S Truman ');

readln;

 

=={{header|F_Sharp|F#}}==

// Collapse a String. Nigel Galloway: June 9th., 2020

//As per the task description a function which 'determines if a character string is collapsible' by testing if any consecutive characters are the same.

collapse " --- Harry S Truman "

collapse "withoutConsecutivelyRepeatedCharacters"

{{out}}

<pre>

 

=={{header|Factor}}==

IN: rosetta-code.string-collapse

 

} [ show-collapse ] each ;

 

{{out}}

(Using some extra test cases from the Go entry.)

=={{header|FreeBASIC}}==

{{trans|BASIC}}

Data ""

Data "'If I were two-faced, would I be wearing this one?' --- Abraham Lincoln "

Next j

Sleep

{{out}}

<pre>

</pre>

 

 

=={{header|Go}}==

 

import "fmt"

fmt.Printf("collapsed: length = %2d, string = «««%s»»»\n\n", clen, cs)

}

 

{{out}}

collapsed: length = 6, string = «««😍😀🙌💃😍🙌»»»

</pre>

=={{header|Groovy}}==

{{trans|Java}}

static void main(String[] args) {

for ( String s : [

return sb.toString()

}

{{out}}

<pre>old: 0 <<<>>>

 

=={{header|Haskell}}==

import Data.Maybe (catMaybes)

import Control.Monad (guard)

main =

mapM_ (\(a, b) -> printf "old: %3d «««%s»»»\nnew: %3d «««%s»»»\n\n" (length a) a (length b) b)

{{out}}

<pre>

Note that we can also directly define a predicate, and a rewrite, in terms of ''Data.List group'',

 

 

isCollapsible :: String -> Bool

 

collapsed :: String -> String

 

or, without imports, in terms of pattern matching:

 

isCollapsible [] = False

isCollapsible [_] = False

collapsed (h:t@(x:_))

| h == x = collapsed t

 

=={{header|J}}==

 

=={{header|Java}}==

// Title: Determine if a string is collapsible

 

 

}

 

{{out}}

 

=={{header|JavaScript}}==

String.prototype.collapse = function() {

let str = this;

console.log(`«««${col}»»» (${col.length})`);

}

 

{{out}} <pre>

=={{header|jq}}==

Here we can use the Unix-like `uniq` function defined on (JSON) arrays to define `collapse` on (JSON) strings:

# Output: a stream

def uniq: foreach .[] as $x ({x:nan, y:.[0]}; {x:$x, y:.x}; select(.x != .y) | .x);

 

 

The program for the given task can now be written in three lines:

 

 

"Original: \(Guillemets) has length \(length)",

(collapse | "Collapsed \(Guillemets) has length \(length)")

 

Using the following invocation on the five "raw" (i.e. unquoted) strings yields the results as shown:

jq -Rrf program.jq raw.txt

 

Collapsed «««»»» has length 0

Original: «««"If I were two-faced, would I be wearing this one?" --- Abraham Lincoln »»» has length 72

Collapsed «««I never give 'em hel, I just tel the truth, and they think it's hel. »»» has length 69

Original: ««« --- Harry S Truman »»» has length 72

 

 

=={{header|Julia}}==

"",

""""If I were two-faced, would I be wearing this one?" --- Abraham Lincoln """,

 

testcollapse(teststrings)

<pre>

«««»»» (length 0)

</pre>

==== Condensed version: ====

"",

""""If I were two-faced, would I be wearing this one?" --- Abraham Lincoln """,

println("«««$s»»» (length $n)\n collapses to:\n«««$t»»» (length $(length(t))).\n")

end

 

=={{header|Kotlin}}==

{{trans|Go}}

val cs = StringBuilder()

var last: Char = 0.toChar()

println()

}

{{out}}

<pre>original : length = 0, string = «««»»»

original : length = 8, string = «««aardvark»»»

collapsed : length = 7, string = «««ardvark»»»</pre>

 

=={{header|Lua}}==

{{trans|C#}}

local ns = ""

local last = nil

end

 

{{out}}

<pre>old: 0 <<<>>>

 

=={{header|Mathematica}} / {{header|Wolfram Language}}==

StringCollapse[s_String] := FixedPoint[StringReplace[y_ ~~ y_ :> y], s]

strings = {"",

,

{s, strings}

{{out}}

<pre>«««»»»

 

=={{header|MATLAB}} / {{header|Octave}}==

function r = collapse(s)

ix=find((s(1:end-1)==s(2:end))+1;

collapse('║ --- Harry S Truman ║', 'r')

 

 

{{out}}

ans = ║ - Hary S Truman ║

PASSES 1 out of 1 test

</pre>

 

=={{header|Nim}}==

 

proc collapse(s: string) =

 

for s in Strings:

 

{{out}}

 

=={{header|Perl}}==

use warnings;

use utf8;

printf "\nLength: %2d <<<%s>>>\nCollapsible: %s\nLength: %2d <<<%s>>>\n",

length($_), $_, $_ ne $squish ? 'True' : 'False', length($squish), $squish

{{out}}

<pre>Length: 0 <<<>>>

If you don't have builtins/punique.e to hand, you may want to take a quick look at squeeze() in

[[https://rosettacode.org/wiki/Determine_if_a_string_is_squeezable#Phix]], but obviously w/o ch.

{{out}}

<pre>

=={{header|PHP}}==

 

 

function collapseString($string) {

echo 'Collapse : string is not collapsing...', PHP_EOL, PHP_EOL;

}

 

{{out}}

The <code>COLLAPSE</code> procedure compares bytes and would be fine with any 8-bit input.

 

BDOS: PROCEDURE (FN, ARG); DECLARE FN BYTE, ARG ADDRESS; GO TO 5; END BDOS;

EXIT: PROCEDURE; CALL BDOS(0,0); END EXIT;

CALL EXIT;

EOF

{{out}}

<pre>0 <<<>>>

 

=={{header|Prolog}}==

collapse_( [A], [A] ).

collapse_( [A,A|T], R ) :- collapse_( [A|T], R ).

string_chars( Str, Chars ),

collapse_( Chars, Result ),

{{out}}

<pre>

 

=={{header|PureBasic}}==

DataSection

STR1:

*p_data+StringByteLength(PeekS(*p_data))+2

Wend

{{out}}

<pre>Before collapse: «««»»» (length: 0)

 

=={{header|Python}}==

 

def collapser(txt):

this = "Collapsed"

sqz = collapser(txt)

 

{{out}}

and for the missing predicate, foregrounded in the task title, and already forgotten in the listing of tests:

 

 

from operator import eq

# MAIN ---

if __name__ == '__main__':

{{Out}}

<pre>[False, True, True, True, True, True, True, True, True, False]</pre>

=={{header|Quackery}}==

 

witheach

[ 2dup = iff

$ "..1111111111111111111111111111111111111111111111111111111111111117777888" task

$ "I never give 'em hell, I just tell the truth, and they think it's hell. " task

 

{{out}}

 

 

</pre>

 

Technically, the task is asking for a boolean. "Determine if a string is collapsible" is answerable with True/False, so return a boolean as well.

 

my $squish = .comb.squish.join;

printf "\nLength: %2d <<<%s>>>\nCollapsible: %s\nLength: %2d <<<%s>>>\n",

AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAA

STRINGS

{{out}}

<pre>Length: 0 <<<>>>

Length: 1 <<<A>>>

</pre>

 

=={{header|REXX}}==

@.= /*define a default for the @. array. */

parse arg x /*obtain optional argument from the CL.*/

$= $ || _ /*append the character, it's different.*/

end /*j*/

{{out|output|text=&nbsp; when using the internal default inputs:}}

<pre>

 

=={{header|Ring}}==

load "stdlib.ring"

 

 

see "done..." + nl

Output:

<pre>

 

done...

</pre>

 

=={{header|Ruby}}==

This is built in since at least a decade under the method name 'squeeze'. squeeze(" ") would only squeeze spaces.

'"If I were two-faced, would I be wearing this one?" --- Abraham Lincoln ',

"..1111111111111111111111111111111111111111111111111111111111111117777888",

puts

end

{{out}}

<pre>«««»»» (size 0)

 

=={{header|Rust}}==

let mut output = String::new();

let mut chars = val.chars().peekable();

println!();

}

{{out}}

<pre>

===Pure imperative programming 😃===

 

 

/**Collapse a string (if possible)*/

 

 

{{out}}

<pre>ORIGINAL : length = 0, string = «««»»»

COLLAPSED : length = 7, string = «««ardvark»»»

This string IS collapsible !</pre>

 

=={{header|Sidef}}==

str.gsub(/(.)\1+/, {|s1| s1 })

}

say "«««#{str}»»» (length: #{str.len})"

say "«««#{ssq}»»» (length: #{ssq.len})\n"

{{out}}

<pre style="font-size: 80%">

=={{header|Smalltalk}}==

{{works with|Smalltalk/X}}

'The better the 4-wheel drive, the further you''ll be from help when ya get stuck!'

'headmistressship'

showCR:( eachWord,'(length:',eachWord size,')' );

showCR:( shortened,'(length:',shortened size,')' ).

{{out}}

<pre>The better the 4-wheel drive, the further you'll be from help when ya get stuck!(length:80)

 

=={{header|Swift}}==

"",

#""If I were two-faced, would I be wearing this one?" --- Abraham Lincoln "#,

for (original, collapsed) in zip(strings, collapsedStrings) {

print (String(format: "%03d «%@»\n%03d «%@»\n", original.count, original, collapsed.count, collapsed))

 

{{out}}

=={{header|Tcl}}==

Please note the ;# ' comments, there appears to be a syntax hightlighting bug with RC

{}

{"If I were two-faced, would I be wearing this one?" --- Abraham Lincoln }

puts ----------------------

}

{{out}}

<pre>

=={{header|Visual Basic .NET}}==

{{trans|C#}}

 

Function Collapse(s As String) As String

End Sub

 

{{out}}

<pre>old: 0 «««»»»

=={{header|VBA}}==

Function :

Dim i As Long, strOut As String

If Len(strIn) > 0 Then

End If

Collapse = strOut

To Call :

Dim S As String

S = vbNullString

Debug.Print "String : <<<" & S & ">>>", "Lenght : " & Len(S)

Debug.Print "Collapsed : <<<" & Collapse(S) & ">>>", "Lenght : " & Len(Collapse(S))

{{out}}

<pre>String : <<<>>> Lenght : 0

String : <<< --- Harry S Truman >>> Lenght : 72

Collapsed : <<< - Hary S Truman >>> Lenght : 17</pre>

 

=={{header|Wren}}==

{{trans|Go}}

{{libheader|Wren-fmt}}

 

// Returns collapsed string, original and new lengths in

System.print("original : length = %(Fmt.d(2, r[1])), string = «««%(s)»»»")

System.print("collapsed: length = %(Fmt.d(2, r[2])), string = «««%(r[0])»»»\n")

 

{{out}}

original : length = 8, string = «««😍😀🙌💃😍😍😍🙌»»»

collapsed: length = 6, string = «««😍😀🙌💃😍🙌»»»

</pre>

 

=={{header|zkl}}==

sink:=Sink(String);

str.reduce('wrap(c1,c2){ if(c1!=c2) sink.write(c2); c2 },""); // prime with \0

cstr:=sink.close();

return(str.len()!=cstr.len(), cstr);

0'^

"If I were two-faced, would I be wearing this one?" --- Abraham Lincoln

_,cstr:=collapsible(s);

println("After: %3d >>>%s<<<\n".fmt(cstr.len(),cstr));

{{out}}

<pre>