È necessario scrivere un programma che valuti una stringa che verrebbe inserita in una calcolatrice avanzata.

Il programma deve accettare input usando stdin ed emettere la risposta corretta. Per le lingue che non dispongono di funzioni per accettare lo stdin, è possibile assumere le funzioni readLinee printgestire queste attività.

Requisiti:

• Non utilizza alcun tipo di funzione "eval"
• Può gestire numeri in virgola mobile e negativi
• Supporta almeno gli operatori +, -, *, / e ^
• Supporta parentesi e parentesi per sovrascrivere l'ordine normale
• Può gestire input contenenti uno o più spazi tra operatori e numeri
• Valuta l'input utilizzando l' ordine standard delle operazioni
  
  

Casi test

Ingresso

10 - 3 + 2

Produzione

9

8 + 6 / 3 - 7 + -5 / 2.5

Produzione

1

4 + [ ( -3 + 5 ) * 3.5 ] ^ 2 - 12

Produzione

41

C ++, 640 583

string k="[]()+-*/^";stack<double> m;stack<char> n;
#define C(o,x,y) ('^'==o?x<y:x<=y)
#define Q(a) double a=m.top();m.pop();
#define R(o) {Q(b)Q(a)m.push(o=='+'?a+b:o=='-'?a-b:o=='*'?a*b:o=='/'?a/b:o=='^'?pow(a,b):0);n.pop();}
while(!cin.eof()){string s;getline(cin,s,' ');if(s.empty())continue;if('\n'==*--s.end())s.erase(--s.end());(s.size()==1&&s.npos!=k.find(s[0]))?({char c=s[0]=='['?'(':s[0]==']'?')':s[0];while(!n.empty()&&'('!= c&&C(c,k.find(c),k.find(n.top())))R(n.top());')'==c?n.pop():n.push(c);}):m.push(strtod(s.c_str(),0));}while(!n.empty())R(n.top());cout<<m.top()<<endl;

frastagliato

string k="[]()+-*/^";
stack<double> m;
stack<char> n;
#define C(o,x,y) ('^'==o?x<y:x<=y)
#define Q(a) double a=m.top();m.pop();
#define R(o) {Q(b)Q(a)m.push(o=='+'?a+b:o=='-'?a-b:o=='*'?a*b:o=='/'?a/b:o=='^'?pow(a,b):0);n.pop();}
while(!cin.eof())
{
    string s;
    getline(cin,s,' ');
    if(s.empty())continue;
    if('\n'==*--s.end())s.erase(--s.end());
    (s.size()==1&&s.npos!=k.find(s[0]))?({
        char c=s[0]=='['?'(':s[0]==']'?')':s[0];
        while(!n.empty()&&'('!= c&&C(c,k.find(c),k.find(n.top())))
            R(n.top());
        ')'==c?n.pop():n.push(c);
    }):m.push(strtod(s.c_str(),0));
}
while(!n.empty())
    R(n.top());
cout<<m.top()<<endl;

Il mio primo codice golf, quindi in attesa di commenti e critiche!

PHP - 394 354 312 caratteri

<?=e(!$s=preg_split('#\s+#',`cat`,-1,1),$s);function e($P,&$s){$S='array_shift';if(($a=$S($s))=='('|$a=='['){$a=e(0,$s);$S($s);}while($s&&($p=strpos(' +-*/^',$o=$s[0]))&&$p>=$P){$b=e($p+($S($s)!='^'),$s);if($o=='+')$a+=$b;if($o=='-')$a-=$b;if($o=='*')$a*=$b;if($o=='/')$a/=$b;if($o=='^')$a=pow($a,$b);}return$a;}

rientrato:

<?
preg_match_all('#\d+(\.\d+)?|\S#',`cat`,$m);
$s=$m[0];
function e($P) {
        global $s;
        if (strpos(" ([",$s[0])){
                array_shift($s);
                $a=e(0);
                array_shift($s);
        } else {
                $a=array_shift($s);
                if ($a=='-')$a.=array_shift($s);
        }
        while ($s && ($p=strpos(' +-*/^',$o=$s[0])) && $p >= $P) {
                array_shift($s);
                $b = e($p+($o!='^'));
                switch($o){
                case'+':$a+=$b;break;
                case'-':$a-=$b;break;
                case'*':$a*=$b;break;
                case'/':$a/=$b;break;
                case'^':$a=pow($a,$b);
                }
        }
        return $a;
}
echo e(0);

Postscript, 446

Questo utilizza l'algoritmo di shunting yard.

[/*[/p
2/e{mul}>>/d[/p
2/e{div}>>/+[/p
1/e{add}>>/-[/p
1/e{sub}>>/o[/p
9/e{}>>/c[/p
-1/e{}>>/^[/p
3/e{exp}>>/p
0>>begin/s(%stdin)(r)file 999 string readline pop def
0 1 s length 1 sub{s exch[0 1 255{}for]dup[(\(o)([o)(\)c)(]c)(/d)]{{}forall
put dup}forall
pop
3 copy pop
get
get
put}for{s token not{exit}if
exch/s exch store{cvr}stopped{load
dup/p get
p
le{currentdict end
exch begin/e get exec}{begin}ifelse}if}loop{{e end}stopped{exit}if}loop
=

Non golfato e commentato:

% We associate the operators with their precedence /p and the executed commend /e
[
  (*)[/p  2 /e{mul}>>
  (d)[/p  2 /e{div}>> % This is division
  (+)[/p  1 /e{add}>>
  (-)[/p  1 /e{sub}>>
  (o)[/p  9 /e{   }>> % This is open bracket
  (c)[/p -1 /e{   }>> % This is close bracket
  (^)[/p  3 /e{exp}>>
  /p 0
>>begin

% Let's read the input string
/s(%stdin)(r)file 999 string readline pop def

% If we want to use the token operator, we have to replace (, [, ), ] and / to get meaningful results
% We use kind of an encoding array (familiar to PostScripters) to map those codes to o, c, and d.
0 1 s length 1 sub{        % index
  s exch                   % string index
  [0 1 255{}for] dup       % string index translationArray translationArray
  [(\(o)  ([o)  (\)c)  (]c)  (/d)] % string index translationArray translationArray reencodeArray
  {                        % string index translationArray translationArray translationString
    {}forall               % string index translationArray translationArray charCode newCharCode
    put dup                % string index translationArray translationArray
  }forall                  % string index translationArray translationArray
  pop                      % string index translationArray
  3 copy pop               % string index translationArray string index
  get                      % string index translationArray charCode
  get                      % string index translatedCharCode
  put                      % -/-
}for

% Now we can actually start interpreting the string
% We use the stack for storing numbers we read and the dictionary stack for operators that are "waiting"
{                          % number*
  s token not{exit}if      % number* string token
  exch /s exch store       % number* token
  % We try to interpret the token as a number
  {cvr}stopped{            % number* token
    % If interpretation as number fails, we have an operator
    load                   % number* opDict
    % Compare operator precedence with last operator on dictstack
    dup /p get             % number* opDict opPrec
    p                      % number* opDict opPrec prevOpPrec
    le {                   % number* opDict
      % If the last operator on the stack has at least the same precedence, execute it
      currentdict end      % number* opDict prevOpDict
      exch begin           % number* prevOpDict
      /e get exec          % number*
    }{                     % number* opDict
      % If last operator doesn't have higher precedence, put the new operator on the dictstack as well
      begin
    }ifelse
  }if
}loop
% If we're finished with interpreting the string, execute all operators that are left on the dictstack
{{e end}stopped{exit}if}loop
=

TODO : giusta associatività dell'espiazione

Python 2 , 339 335 byte

import re
x,s=input(),re.sub
def f(y):
 y,r=s('- ','+ -',y).split(),['^','*','/','+','-']
 for c in r:
  while c in y:d=y.index(c)-1;a,b=map(float,[y[d],y[d+2]]);y=y[:d]+[((a,-a)[a<0]**b,a*b,a/b,a+b,a-b)[r.index(c)]]+y[d+3:]
 return`y[0]`
w=lambda b:s("[([]+[\d+\-*/^ .]*[)\]]",lambda m:f(m.group()[1:]),s(' +',' ',b))
print f(w(w(x)))

Provalo online!

• -4 byte modificando str (x) con i backtick ``!

Postscript, 1000 695 665 494

Ho rubato idee a ThomasW. Funzionalità aggiunta: accetta stringhe con o senza spazi attorno agli operatori.[funzione rimossa]

L'utilizzo ARGUMENTSè più breve di %stdin, e più facile da testare, per l'avvio!

Sostituzione semplificata per sostituire solo le parentesi con parentesi.

575(1)10:36 PM:ps 0> gsnd -q -- calc2bg.ps '10 - 3 + 2'
9
576(1)10:37 PM:ps 0> gsnd -q -- calc2bg.ps '8 + 6 / 3 - 7 + -5 / 2.5'
1.0
577(1)10:37 PM:ps 0> gsnd -q -- calc2bg.ps '4 + [ ( -3 + 5 ) * 3.5 ] ^ 2 - 12'
41.0

Codice:

/T[/^[/C{exp}/P 4/X{le}>>/*[/C{mul}/P 3/X{lt}>>/[/C{div}/P
3/X{lt}>>/+[/C{add}/P 2/X{lt}>>/-[/C{sub}/P
2/X{lt}>>>>def[/integertype{}/realtype{}/stringtype{V}/nametype{cvlit/N
exch store{P T N get dup/P get exch/X get exec{exit}if C end}loop T N get
begin}91 40 93 41>>begin/V{0 1 2 index length 1 sub{2 copy get
dup where{exch get}if 3 copy put pop pop}for[/N 0/R 0/P 0/C{}>>begin{token
not{exit}if exch/R exch store dup type exec R}loop{P 0 eq{end exit}if C
end}loop}def ARGUMENTS{V ==}forall

Ungolf e commentato:

%!
%Shunting-Yard Algorithm using dictstack for operators
%invoke with %gsnd -q -- calc2bg.ps [ 'expr1' ]*

%The operator table. C:code P:precedence X:test(implements associativity)
/T[
    /^[/C{exp}/P 4/X{le}>>
    /*[/C{mul}/P 3/X{lt}>>
    /[/C{div}/P 3/X{lt}>>
    /+[/C{add}/P 2/X{lt}>>
    /-[/C{sub}/P 2/X{lt}>>
>>def

%The type-dispatch dictionary
%numbers: do nothing
%string: recurse
%name: process op
[%/integertype{}/realtype{} %now uses `where` below
/stringtype{V}/nametype{
pstack()=
    cvlit/N exch store %stash cur-op
    {
        P %prec(tos)
        T N get %prec(tos) cur-op-dict
        dup/P get %prec(tos) cur-op-dict prec(cur-op)
        exch/X get %prec(tos) prec(cur-op) test(cur-op)
        exec{exit}if %exit if prec(tos) < || <= prec(cur-op)
/C load ==
        C %pop-and-apply
        end
pstack()=
    } loop
    T N get begin %push cur-op
}>>begin

%substitutions
[91 40 93 41>>begin %replace brackets with parens
/V {
    %pre-process
    0 1 2 index length 1 sub {
        2 copy get
        dup where { exch get } if
        3 copy put pop pop
    } for
dup ==

    [/N 0/R 0/P 0/C{}>>begin %dummy base operator and storage
    { token not{exit}if exch /R exch store %extract token, stash Remainder
pstack(>)=
        %dispatch type procedure
        dup type dup where { pop exec }{ pop } ifelse
    R }loop
pstack()=
    {
        P 0 eq{end exit}if %hit dummy op: exit
/C load ==
        C end %pop and apply
    } loop
} def

ARGUMENTS{V ==}forall %iterate through the command-line arguments