Scrivi un programma o una funzione che:

1. accetta una stringa da stdio o argomenti
2. sostituisce tutte le occorrenze di truecon falsee falsecontrue
3. lo inverte, ma non inverte trueefalse
4. restituisce o stampa il risultato

Esempi (viene inserito il lato sinistro):

"true"                     "false"
"2false"                   "true2"
"true is false"            "true si false"
"false,true,undefined"     "denifednu,false,true"
"stressed-false"           "true-desserts"
"falstrue"                 "falseslaf"
"true false true x"        "x false true false"

Si applicano scappatoie standard. Questo è code-golf , quindi vince il codice più breve in byte.

Classifica

var QUESTION_ID=63256,OVERRIDE_USER=20569;function answersUrl(e){return"http://api.stackexchange.com/2.2/questions/"+QUESTION_ID+"/answers?page="+e+"&pagesize=100&order=desc&sort=creation&site=codegolf&filter="+ANSWER_FILTER}function commentUrl(e,s){return"http://api.stackexchange.com/2.2/answers/"+s.join(";")+"/comments?page="+e+"&pagesize=100&order=desc&sort=creation&site=codegolf&filter="+COMMENT_FILTER}function getAnswers(){jQuery.ajax({url:answersUrl(answer_page++),method:"get",dataType:"jsonp",crossDomain:!0,success:function(e){answers.push.apply(answers,e.items),answers_hash=[],answer_ids=[],e.items.forEach(function(e){e.comments=[];var s=+e.share_link.match(/\d+/);answer_ids.push(s),answers_hash[s]=e}),e.has_more||(more_answers=!1),comment_page=1,getComments()}})}function getComments(){jQuery.ajax({url:commentUrl(comment_page++,answer_ids),method:"get",dataType:"jsonp",crossDomain:!0,success:function(e){e.items.forEach(function(e){e.owner.user_id===OVERRIDE_USER&&answers_hash[e.post_id].comments.push(e)}),e.has_more?getComments():more_answers?getAnswers():process()}})}function getAuthorName(e){return e.owner.display_name}function process(){var e=[];answers.forEach(function(s){var r=s.body;s.comments.forEach(function(e){OVERRIDE_REG.test(e.body)&&(r="<h1>"+e.body.replace(OVERRIDE_REG,"")+"</h1>")});var a=r.match(SCORE_REG);a&&e.push({user:getAuthorName(s),size:+a[2],language:a[1],link:s.share_link})}),e.sort(function(e,s){var r=e.size,a=s.size;return r-a});var s={},r=1,a=null,n=1;e.forEach(function(e){e.size!=a&&(n=r),a=e.size,++r;var t=jQuery("#answer-template").html();t=t.replace("{{PLACE}}",n+".").replace("{{NAME}}",e.user).replace("{{LANGUAGE}}",e.language).replace("{{SIZE}}",e.size).replace("{{LINK}}",e.link),t=jQuery(t),jQuery("#answers").append(t);var o=e.language;/<a/.test(o)&&(o=jQuery(o).text()),s[o]=s[o]||{lang:e.language,user:e.user,size:e.size,link:e.link}});var t=[];for(var o in s)s.hasOwnProperty(o)&&t.push(s[o]);t.sort(function(e,s){return e.lang>s.lang?1:e.lang<s.lang?-1:0});for(var c=0;c<t.length;++c){var i=jQuery("#language-template").html(),o=t[c];i=i.replace("{{LANGUAGE}}",o.lang).replace("{{NAME}}",o.user).replace("{{SIZE}}",o.size).replace("{{LINK}}",o.link),i=jQuery(i),jQuery("#languages").append(i)}}var ANSWER_FILTER="!t)IWYnsLAZle2tQ3KqrVveCRJfxcRLe",COMMENT_FILTER="!)Q2B_A2kjfAiU78X(md6BoYk",answers=[],answers_hash,answer_ids,answer_page=1,more_answers=!0,comment_page;getAnswers();var SCORE_REG=/<h\d>\s*([^\n,]*[^\s,]),.*?(\d+)(?=[^\n\d<>]*(?:<(?:s>[^\n<>]*<\/s>|[^\n<>]+>)[^\n\d<>]*)*<\/h\d>)/,OVERRIDE_REG=/^Override\s*header:\s*/i;

body{text-align:left!important}#answer-list,#language-list{padding:10px;width:290px;float:left}table thead{font-weight:700}table td{padding:5px}

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script> <link rel="stylesheet" type="text/css" href="//cdn.sstatic.net/codegolf/all.css?v=83c949450c8b"> <div id="answer-list"> <h2>Leaderboard</h2> <table class="answer-list"> <thead> <tr><td></td><td>Author</td><td>Language</td><td>Size</td></tr></thead> <tbody id="answers"> </tbody> </table> </div><div id="language-list"> <h2>Winners by Language</h2> <table class="language-list"> <thead> <tr><td>Language</td><td>User</td><td>Score</td></tr></thead> <tbody id="languages"> </tbody> </table> </div><table style="display: none"> <tbody id="answer-template"> <tr><td>{{PLACE}}</td><td>{{NAME}}</td><td>{{LANGUAGE}}</td><td>{{SIZE}}</td><td><a href="{{LINK}}">Link</a></td></tr></tbody> </table> <table style="display: none"> <tbody id="language-template"> <tr><td>{{LANGUAGE}}</td><td>{{NAME}}</td><td>{{SIZE}}</td><td><a href="{{LINK}}">Link</a></td></tr></tbody> </table>

C # 6, 144 byte

string R(string t)=>string.Concat(new System.Text.RegularExpressions.Regex("true|false").Replace(t,m=>m.Value[0]<'g'?"eurt":"eslaf").Reverse());

Utilizza un'espressione regolare per la corrispondenza true|falsee se corrisponde trueverrà sostituita da eslaf, altrimenti da eurt. m.Value[0]<'g'è un modo più breve per dirlo m.Value[0]=="false", perché gli unici valori possibili per m.Valuesono "true"o "false", quindi se il codice char del primo carattere è più piccolo del codice char di 'g', è "false".

Vecchia versione, 95 byte

Questo aveva un bug, non restituiva un output corretto per falstrue.

string R(string t)=>string.Concat(t.Reverse()).Replace("eurt","false").Replace("eslaf","true");

TeaScript , 36 25 24 byte

xv¡g("eurt|eslaf",#ln>4)   

TeaScript è JavaScript per il golf.

Modifiche: salvato 11 byte grazie a @ Vɪʜᴀɴ. Risolto per input falstruee salvato un byte.

Vecchia versione (non valida):

xv¡g("eurt",f)g(f.T¡v¡,t)

Spiegazione:

x    // Input
 v¡    // Reverse
   g("eurt",    // Global replace "eurt" with "false".
            f)    // f is predefined to false.
              g(f.T¡v¡, // Convert false to string, then reverse.
                       t) // t is predefined to true.

Bash + GNU, 45 38 73 byte

Modifica: funziona con entrambi trufalseefalstrue

sed s/false/%eurt%/g\;s/true/%eslaf%/g|rev|sed "s/%\(true\|false\)%/\1/g"

Vecchia versione , 38 byte (abbreviata, grazie a Digital Trauma):

rev|sed s/eurt/false/g\;s/eslaf/true/g

JavaScript ES6, 59

Come una funzione anonima.

Nota, sostituire è usato solo come scorciatoia per match (). Map (). La stringa sostituita viene scartata e la stringa di output viene creata pezzo per pezzo all'indietro (quindi non è necessario invertire).

s=>s.replace(/false|true|./g,x=>s=(x[1]?x<'t':x)+s,s='')&&s

Prova a eseguire lo snippet di seguito in un browser compatibile con EcmaScript 6.

f=s=>s.replace(/false|true|./g,x=>s=(x[1]?x<'t':x)+s,s='')&&s

//test

console.log=x=>O.innerHTML+=x+'\n'

;[
 ["true","false"]
,["falstrue","falseslaf"]  
,["1false","true1"]
,["true is false","true si false"]
,["false,true,undefined","denifednu,false,true"]
,["stressed-false","true-desserts"]
,["true false true x","x false true false"]
].forEach(t=>console.log(t[0]+' -> '+f(t[0])))

<pre id=O></pre>

Batch di Windows, 184 213 byte

Risolto il bug falstrue -> falseslafetrufalse -> trueurt

Probabilmente una delle lingue meno popolari:

setlocal enabledelayedexpansion
set /p Q=
set N=0
:L
call set T=%%Q:~%N%,1%%%
set /a N+=1
if not "%T%" equ "" (
set R=%T%%R%
goto L
)
set R=%R:eurt=false%
set R=%R:eslaf=true%
set R=%R:falstrue=falseslaf%
echo %R%

Haskell, 94 byte

Esegue la corrispondenza del modello sulla stringa di input, cercando "false" o "true" e aggiunge il contrario al risultato dell'applicazione della funzione sul resto della stringa. Se non viene trovato vero o falso, utilizza la ricorsione per invertire la stringa nello stesso modo.

f[]=[]
f('t':'r':'u':'e':s)=f s++"false"
f('f':'a':'l':'s':'e':s)=f s++"true"
f(x:s)=f s++[x]

JavaScript ES6, 95 93 byte

Funzione senza nome. Aggiungi f=all'inizio per usarlo. Grazie Ismael! Presuppone inoltre che l'input non contenga schede.

x=>[...x[r="replace"](/false/g,"\teslaf")[r](/(\t)*true/g,"eurt")[r](/\t/g,"")].reverse().join``

Pyth, 30 byte

::_z"eurt""false""eslaf""true"

Ciò inverte input ( _z), sostituisce "eurt"per "false"e "eslaf"per "true". La sostituzione viene eseguita utilizzando :.

Provalo online

rs , 56 byte

\t
+(.*\t)(.)(.*)/\2\1\3
\t/
eurt/fals\t
eslaf/true
\t/e

Demo live e casi di test.

Julia, 59 55 46 byte

s->replace(reverse(s),r"eurt|eslaf",i->i<"et")

Ciò crea una funzione senza nome che accetta una stringa e restituisce una stringa. Per chiamarlo, dagli un nome, ad es f=s->....

The input is reversed using reverse. We match on the regular expression eurt|eslaf which matches true or false backwards. To the match we apply a function that returns true if the match is lexicographically smaller than et (i.e. eslaf) and false otherwise. The boolean literals are converted to string in the output.

Saved 9 bytes and fixed an issue thanks to Glen O!

Javascript, 135 Bytes

function(s){return s.split("").reverse().join("").replace(/eslaf/i,'☺').replace(/eurt/i,'☻').replace(/☻/g,!1).replace(/☺/g,!1)}

Test:

=>"false is the opposite of true"

<="true fo etisoppo eht si false"

Thanks ProgramFOX and edc65 for pointing out a bug!

Java, 162 98 92 bytes

Thanks (and sorry!~) to @DanielM. for telling me about StringBuffer and the fact that we can use functions!

Because, you know, Java.

s->(""+new StringBuffer(s.replaceAll("false","eurt")).reverse()).replaceAll("eurt","false");

Returns the correct, reversed string.

Ungolfed Version:

s->new StringBuilder(
    s.replaceAll("false","eurt"))
    .reverse().toString().replaceAll("eurt","false");

Basically, I replace all instances of "false" with a backwards "true", then reverse the entire string, and then replace the now backwards versions of "true" (not the ones I just replaced) with "false". Easy peasy.

Mathematica, 64 bytes

StringReverse@#~StringReplace~{"eurt"->"false","eslaf"->"true"}&

Python 3, 68 100 bytes

I'm still golfing it, but it's fixed to the bug, so falstrue -> falselsaf and trufalse -> trueurt

Pretty straightforward:

print(input()[::-1].replace("eurt","false").replace("eslaf","true").replace("falstrue","falseslaf"))

Japt, 26 bytes

Note: This may be invalid, as it requires bug fixes made after this challenge was posted.

Uw r"eurt|eslaf",X=>X<"et"

Try it in the online interpreter! (Arrow function requires ES6-compliant browser, such as Firefox.)

How it works

             // Implicit: U = input string
Uw r         // reverse U, then replace:
"eurt|eslaf" // occurrences of either "eurt" or "eslaf"
X=>X<"et"    // with "false" or "true", respectively
             // Implicit: output last expression

Here's a version that worked before the bug fixes: (38 bytes)

Uw $.replace(/eurt|eslaf/g,X=>X<"et")$

Gema, 43

*=@a{@reverse{*}};a:eurt=false;a:eslaf=true

(Gema is an obscure macro language.)

Pyth, 28 22

Amr`!dZ2jHjLGcR_Hc_z_G

6 bytes thanks to Jakube

Works correctly for falstrue, as shown in the suite below.

Test suite

Haskell, 102 bytes

h('t':'r':'u':'e':s)="eslaf"++h s
h('f':'a':'l':'s':'e':s)="eurt"++h s
h(x:s)=x:h s
h[]=""
r=reverse.h

The replacement of "true" by "false" and vice-versa is quite lengthy with the pattern-matching, but at least it deals correctly with "falstrue" and the like. And besides, I suspect that a correct regex-based version would be a bit longer.

Python 3 - 108 92 bytes

import re
print(re.sub("eslaf|eurt",lambda m:repr(len(m.group(0))>4).lower(),input()[::-1]))

Uses a regex to match on "true" or "false" and uses a lambda to process matches and choose what to use as a replacement string. Using repr gets the string representation of (len(match)>4) which gives "True" when "false" is matched and vice versa (and use .lower() because repr(bool) gives a capitalized string) to get the inverse of the match and finish up by reversing the replacement and then the processed input using [::-1]

Managed to get the length down 16 bytes from TFelds suggestions.

Edit: Python is back in front of java, no need for alarm.

𝔼𝕊𝕄𝕚𝕟, 40 chars / 65 bytes

ô[…ïċ/false|true/g,⇏[…⬯+!שúa]ù⬮ø⬯)]ù⬮ø⬯)

Try it here (Firefox only).

Thanks to @feersum for pointing out a bug!

21 chars / 43 bytes, non-competitive

ôᴙ(ïċ/⊭|⊨⌿,↪ᴙ(⬯+!ë$⸩⸩

Try it here (Firefox only).

Prolog, 225 bytes

p(X):-string_to_list(X,L),reverse(L,B),q(B,C),string_to_list(Z,C),write(Z),!.
q([],[]).
q([101,117,114,116|T],[102,97,108,115,101|L]):-q(T,L).
q([101,115,108,97,102|T],[116,114,117,101|L]):-q(T,L).
q([H|T],[H|L]):-q(T,L).

Try it out online here
Run by querying in the following way:

p("falstrue").

Ruby, 55 bytes

->s{s.gsub(/true|false/){$&[?t]?:eslaf: :eurt}.reverse}

Test:

->s{s.gsub(/true|false/){$&[?t]?:eslaf: :eurt}.reverse}["false,true,undefined"]
=> "denifednu,false,true"

Perl 5, 68 bytes

67 plus 1 for -E instead of -e

%a=(false,eurt,true,eslaf);say~~reverse<>=~s/false|true/$a{$&}/gr

OpenSCAD, 178 bytes

(Note that this uses the String Theory library, as OpenSCAD doesn't exactly have a standard library. Additionally, this is a function because the only allowed input is to hard-code it.

use <Strings.scad>;function f(a)=contains(g(a),"eurt")?replace(g(a),"eurt","false"):g(a);function g(a)=contains(reverse(a),"eslaf")?replace(reverse(a),"eslaf","true"):reverse(a);

C#, 260 bytes

using System;class P{static void Main(){var y=Console.ReadLine();char[] n=y.ToCharArray();Array.Reverse(n);var s=new string(n);if(s.Contains("eslaf")){s=s.Replace("eslaf","true");}if(s.Contains("eurt")){s=s.Replace("eurt","false");}Console.WriteLine(s);}}

PHP, 60 bytes

Simple, reverses the string first, then replaces the reversed versions with their respective swaps.

"falstrue" becomes "eurtslaf" becomes "falseslaf".

<?=strtr(strrev($argv[1]),{'eurt'=>'false','eslaf'=>'true'})

Perl 5.10, 54 bytes

$_=reverse<>;s/(eurt)|(eslaf)/$1?"false":"true"/eg;say

Reverse, then replace. A different way of doing it besides the hash table used for the other Perl answer, which ends up being shorter!

Try it online.

Pyth - 18 bytes

Can be golfed a lot more.

Amr`!dZ2::_z_GH_HG

Test Suite.