for the 2nd one, 我的作業。（俺剛寫的，還沒調試：）

2)Write a function to print a number in binary form.

void BinaryPrint( long decNumber)
{

long appearanceBinNum = 0L;
long decMultiplier = 1L;
while (decNumber > 0)
{
appearanceBinNum += decMultiplier*( decNumber %2);
decNumber /= 2;
decMultiplier *= 10;
}

cout return;

}