Sunday字符串搜索算法Delphi实现

Sunday算法描述

这玩意儿有人实现过，作为验证再稍微美化了一下：

function PosEx(KeyStr, TextStr: string): Integer;var  I: Integer;  KeyLen, BuffLen: Integer;  function Match(N: Integer): Boolean;  var    J: Integer;  begin    Result := True;    for J := 0 to KeyLen - 1 do      if TextStr[J + N] <> KeyStr[J + 1] then begin        Result := False;        Exit;      end;  end;begin  Result := 0;  I := 1;  KeyLen := Length(KeyStr);  BuffLen := Length(TextStr);  while not Match(I) do  begin    if I > BuffLen then Break;    if Pos(TextStr[I + KeyLen], KeyStr) <> 0 then begin      I := I + 1 + KeyLen - Pos(TextStr[I + KeyLen], KeyStr);    end else begin      I := I + KeyLen;    end;  end;  if Match(I) then    Result := I;end;