Convert decimal to binary string

To complete a CRC (Cyclic Redundancy checksum) coding task assigned by the instructor today, a subroutine is to be converted from decimal to binary string for display! Don't do it, don't know ~~~ It turned out that I had no temper after debugging ~~!! I can't think of it as simple as I thought it was actually a lot of things to consider ~~~ Almost got hit ~~~ (For convenience, use the cstring class in MFC)

 

// Convert decimal to binary
Void CCRC: dectobinary (cstring & changestring)
{

// Convert the number of string type to a long integer.
Unsigned long num = atol (changestring. getbuffer (changestring. getlength ()));
Unsigned long temp = 1;

Int K = 0;

// Obtain the power no greater than the current number, and set the string length.
While (temp <num)
{
K ++;
Temp * = 2;
}

// Reset the string length

Changestring. getbuffersetlength (k );
Changestring. setat (0, '1 ');

Temp/= 2;
Num-= temp;
 
K = 1;

// When the number of conversions is greater than 0, find a two-power number not greater than num,
While (Num> = 0 & temp! = 0)
{
Temp/= 2; // This sentence is very important
While (Num <temp)
{

// If temp is smaller than num, set it to 0.
Changestring. setat (K ++, '0 ');
Temp/= 2;
}

// This condition is used to process the last bit.
If (num! = 0)
Changestring. setat (K ++, '1 ');
Num-= temp;
 
}

}