十进制转换为十六进制

string MySystem::DecToHex(int n)
{
long long Temp = static_cast<long long>(n);
if (Temp<0)
{
Temp = UINT_MAX + n + 1;
}
string Result("0X");
//保存匹配的结果
char Map[] = { '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', 'A', 'B', 'C', 'D', 'E', 'F' };
while (Temp)
{
Result += Map[Temp % 16];
Temp /= 16;
}
int i = 2;
int j = Result.size() - 1;
while (i<j)
{
swap(Result[i], Result[j]);
++i;
--j;
}
return Result;
}