十進制與十六進制轉換（面試題）

面試的時候遇到這道題，居然做不對，有點鬱悶

 

1、十六進制轉十進制
long HexToDem(unsigned long HexNum)
{
  long DemNum=0;
  char string[8];
  sprintf(string,"%ld",HexNum);
  DemNum=atol(string);
  return DemNum;
}
2、十進制字符串轉十六進制
CString DecToHex(CString strDec)
{
double dblData = 0;
char chsData[128];
CString strHec;
sscanf(strDec.GetBuffer(strDec.GetLength()),"%f",&dblData);
strHec.Format("%x", dblData);

return strHec;
}
3、十進制轉十六進制
CString CSegInfo::algorismtohex(int algorism)//十六進制轉換
{
CString str;
switch(algorism)
{
case 10:
str="A";
break;
case 11:
str="B";
break;
case 12:
str="C";
break;
case 13:
str="D";
break;
case 14:
str="E";
break;
case 15:
str="F";
break;
default:
str.Format("%d",algorism);
}
return str;
}
void mydialog::OnButton()
{UpdateData();
m_edit2=algorismtohex(m_edit1);]
UpdateData(FALSE);
}
edit1 int型
edit2 CString型