文字列の中子列の個数を判断する関数
1628 ワード
unit Unit1;
interface
uses
Windows, Messages, SysUtils, Variants, Classes, Graphics, Controls, Forms,
Dialogs;
type
TForm1 = class(TForm)
procedure FormCreate(Sender: TObject);
end;
var
Form1: TForm1;
implementation
{$R *.dfm}
{ }
function GetSubStrNum(SubStr,Str: string): Integer;
begin
Result := 0;
while Pos(SubStr, Str) > 0 do
begin
Str := Copy(Str, Pos(SubStr,Str)+1, Length(Str));
Inc(Result);
end;
end;
{ }
procedure TForm1.FormCreate(Sender: TObject);
var
s1,s: string;
begin
s1 := ' ';
s := ' ';
ShowMessage(IntToStr(GetSubStrNum(s1,s))); {3}
end;
end.
再最適化:
function GetSubStrNum(const SubStr,Str: WideString): Integer;
var
pw: PWideChar;
i,SubLen: Integer;
begin
Result := 0;
pw := PWideChar(Str);
SubLen := Length(SubStr);
while i > 0 do
begin
i := Pos(SubStr, pw);
Inc(pw, i - 1 + SubLen);
if Boolean(i) then Inc(Result);
end;
end;
これは「道法自然」兄のコードです.
function GetSubStrNum(const SubStr, Str: widestring ): Integer;
var
i,x: Integer;
Len,LenSubStr: Integer;
begin
Result := 0;
i := 1;
LenSubStr := Length(SubStr);
Len := Length(Str) - LenSubStr + 1;
while i <= Len do
begin
if Str[i] = SubStr[1] then
begin
x := 1;
while (x < LenSubStr) and (Str[i+x] = SubStr[x+1]) do Inc(x);
if (x = LenSubStr) then Result := Result + 1;
Inc(i,x);
end else Inc(i);
end;
end;