Доброго времени суток, форумчане!
Помогите переделать пару строк с pascal На c++. В pascale не особо сильна, поэтому для меня составляет некоторую сложность переписать следующий код
| Код |
unit Recognition;
interface
uses
Windows, Messages, SysUtils, Classes, Graphics, Controls,
Forms, Dialogs, Math;
type
TVar = set of char;
procedure Preparation(var s: string; variables: TVar);
function ChangeVar(s: string; c: char; value: extended): string;
function Recogn(st: string; var Num: extended): boolean;
implementation
procedure Preparation(var s: string; variables: TVar);
const
operators: set of char = ['+','-','*', '/', '^'];
var
i: integer;
figures: set of char;
begin
figures := ['0','1','2','3','4','5','6','7','8','9', DecimalSeparator] + variables;
// " "
repeat
i := pos(' ', s);
if i <= 0 then
break;
delete(s, i, 1);
until
1 = 0;
s := LowerCase(s);
// ".", ","
if DecimalSeparator = '.' then
begin
i := pos(',', s);
while i > 0 do
begin
s[i] := '.';
i := pos(',', s);
end;
end
else
begin
i := pos('.', s);
while i > 0 do begin
s[i] := ',';
i := pos('.', s);
end;
end;
// Pi
repeat
i := pos('pi', s);
if i <= 0 then
break;
delete(s, i, 2);
insert(FloatToStr(Pi), s, i);
until
1 = 0;
// ":"
repeat
i := pos(':', s);
if i <= 0 then
break;
s[i] := '/';
until
1 = 0;
// |...|
repeat
i := pos('|', s);
if i <= 0 then
break;
s[i] := 'a';
insert('bs(', s, i + 1);
i := i + 3;
repeat
i := i + 1
until
(i > Length(s)) or (s[i] = '|');
if s[i] = '|' then
s[i] := ')';
until
1 = 0;
// #...#
i := 1;
repeat
if s[i] in figures then
begin
insert('#', s, i);
i := i + 2;
while (s[i] in figures) do
i := i + 1;
insert('#', s, i);
i := i + 1;
end;
i := i + 1;
until
i > Length(s);
end;
function ChangeVar(s: string; c: char; value: extended): string;
var
p: integer;
begin
result := s;
repeat
p := pos(c, result);
if p <= 0 then
break;
delete(result, p, 1);
insert(FloatToStr(value), result, p);
until
1 = 0;
end;
function Recogn(st: string; var Num: extended): boolean;
const
pogr = 1E-5;
var
p, p1: integer;
i, j: integer;
v1, v2: extended;
func: (fNone, fSin, fCos, fTg, fCtg, fArcsin, fArccos,
fArctg, fArcctg, fAbs, fLn, fLg, fExp);
Sign: integer;
s: string;
s1: string;
function FindLeftValue(p: integer; var Margin: integer;
var Value: extended): boolean;
var
i: integer;
begin
i := p - 1;
repeat
i := i - 1
until
(i <= 0) or (s[i] = '#');
Margin := i;
try
Value := StrToFloat(copy(s, i + 1, p - i - 2));
result := true;
except
result := false
end;
delete(s, i, p - i);
end;
function FindRightValue(p: integer; var Value: extended): boolean;
var
i: integer;
begin
i := p + 1;
repeat
i := i + 1
until
(i > Length(s)) or (s[i] = '#');
i := i - 1;
s1 := copy(s, p + 2, i - p - 1);
result := TextToFloat(PChar(s1), value, fvExtended);
delete(s, p + 1, i - p + 1);
end;
procedure PutValue(p: integer; NewValue: extended);
begin
insert('#' + FloatToStr(v1) + '#', s, p);
end;
begin
Result := false;
s := st;
// ()
p := pos('(', s);
while p > 0 do
begin
i := p;
j := 1;
repeat
i := i + 1;
if s[i] = '(' then
j := j + 1;
if s[i] = ')' then
j := j - 1;
until
(i > Length(s)) or (j <= 0);
if i > Length(s) then
s := s + ')';
if Recogn(copy(s, p + 1, i - p - 1), v1) = false then
Exit;
delete(s, p, i - p + 1);
PutValue(p, v1);
p := pos('(', s);
end;
// sin, cos, tg, ctg, arcsin, arccos, arctg, arcctg, abs, ln, lg, log, exp
repeat
func := fNone;
p1 := pos('sin', s);
if p1 > 0 then
begin
func := fSin;
p := p1;
end;
p1 := pos('cos', s);
if p1 > 0 then
begin
func := fCos;
p := p1;
end;
p1 := pos('tg', s);
if p1 > 0 then
begin
func := fTg;
p := p1;
end;
p1 := pos('ctg', s);
if p1 > 0 then
begin
func := fCtg;
p := p1;
end;
p1 := pos('arcsin', s);
if p1 > 0 then
begin
func := fArcsin;
p := p1;
end;
p1 := pos('arccos', s);
if p1 > 0 then
begin
func := fArccos;
p := p1;
end;
p1 := pos('arctg', s);
if p1 > 0 then
begin
func := fArctg;
p := p1;
end;
p1 := pos('arcctg', s);
if p1 > 0 then
begin
func := fArcctg;
p := p1;
end;
p1 := pos('abs', s);
if p1 > 0 then
begin
func := fAbs;
p := p1;
end;
p1 := pos('ln', s);
if p1 > 0 then
begin
func := fLn;
p := p1;
end;
p1 := pos('lg', s);
if p1 > 0 then
begin
func := fLg;
p := p1;
end;
p1 := pos('exp', s);
if p1 > 0 then
begin
func := fExp;
p := p1;
end;
if func = fNone then
break;
case func of
fSin, fCos, fCtg, fAbs, fExp: i := p + 2;
fArctg: i := p + 4;
fArcsin, fArccos, fArcctg: i := p + 5;
else
i := p + 1;
end;
if FindRightValue(i, v1) = false then
Exit;
delete(s, p, i - p + 1);
case func of
fSin: v1 := sin(v1);
fCos: v1 := cos(v1);
fTg:
begin
if abs(cos(v1)) < pogr then
Exit;
v1 := sin(v1) / cos(v1);
end;
fCtg:
begin
if abs(sin(v1)) < pogr then
Exit;
v1 := cos(v1) / sin(v1);
end;
fArcsin:
begin
if Abs(v1) > 1 then
Exit;
v1 := arcsin(v1);
end;
fArccos:
begin
if abs(v1) > 1 then
Exit;
v1 := arccos(v1);
end;
fArctg: v1 := arctan(v1);
// fArcctg: v1 := arcctan(v1);
fAbs: v1 := abs(v1);
fLn:
begin
if v1 < pogr then
Exit;
v1 := Ln(v1);
end;
fLg:
begin
if v1 < 0 then
Exit;
v1 := Log10(v1);
end;
fExp: v1 := exp(v1);
end;
PutValue(p, v1);
until
func = fNone;
// power
p := pos('^', s);
while p > 0 do
begin
if FindRightValue(p, v2) = false then
Exit;
if FindLeftValue(p, i, v1) = false then
Exit;
if (v1 < 0) and (abs(Frac(v2)) > pogr) then
Exit;
if (abs(v1) < pogr) and (v2 < 0) then
Exit;
delete(s, i, 1);
v1 := Power(v1, v2);
PutValue(i, v1);
p := pos('^', s);
end;
// *, /
p := pos('*', s);
p1 := pos('/', s);
if (p1 > 0) and ((p1 < p) or (p <= 0)) then
p := p1;
while p > 0 do
begin
if FindRightValue(p, v2) = false then
Exit;
if FindLeftValue(p, i, v1) = false then
Exit;
if s[i] = '*' then
v1 := v1 * v2
else
begin
if abs(v2) < pogr then
Exit;
v1 := v1 / v2;
end;
delete(s, i, 1);
PutValue(i, v1);
p := pos('*', s);
p1 := pos('/', s);
if (p1 > 0) and ((p1 < p) or (p <= 0)) then
p := p1;
end;
// +, -
Num := 0;
repeat
Sign := 1;
while (Length(s) > 0) and (s[1] <> '#') do
begin
if s[1] = '-' then
Sign := -Sign
else
if s[1] <> '+' then
Exit;
delete(s, 1, 1);
end;
if FindRightValue(0, v1) = false then
Exit;
if Sign < 0 then
Num := Num - v1
else
Num := Num + v1;
until
Length(s) <= 0;
Result := true;
end;
end.
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Или подскажите алгоритм парсинга формулы типа у=cos(x)+4, введного в edit. правда на С++.
Заранее спасибо!
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