Hello,
I'm trying to write a recursive function to convert a decimal unsigned char to binary notation. Only problem is that I don't know what stopping condition I could implement.
It can't be when my number is 0, because it's an unsigned char, it goes automatically to 255 when it reaches zero. Anyone got an idea?
No. zero is not 255.
0 would be the stopping condition to look for, divide the number by 2 until nothing is left.
One way to do a loop for an unsigned variable from 255 down to zero:The concept is similar to that of a reverse iterator in C++, where it internally actually points at the item after the one you want. Here it appears to start at 256 and go down until 1, but due to the i-- that is excuted at the startt of each loop, the valu inside the loop is one less than that.Code:for (unsigned int i=256; i-- > 0;)
My homepage
Advice: Take only as directed - If symptoms persist, please see your debugger
Linus Torvalds: "But it clearly is the only right way. The fact that everybody else does it some other way only means that they are wrong"
Pass in a "bits left to convert" parameter. Decrement it each time, until it's zero:
Code:print_binary(unsigned char x, int bits_left) { if bits_left > 0 print bit print_binary(x/2, bits_left-1) } ... print_binary(42, 8) // print the number 42 in binary, it has 8 bits
I'm not sure why you'd need to keep track of the bits left, since your constant dividing by 2 does that for you. Once x hits zero, you don't need to go again.
Quzah.
Hope is the first step on the road to disappointment.
I was imagining the OP always wanted 8 digits printed, in which case, any number less than 128 would print fewer digits if the stop condition was simply x > 0. I suppose that wasn't specified, so it may not be necessary. In any case, I just realized my code will print them in reverse if printing the LSB. Oh well, the OP can sort that out for himself if need be.Originally Posted by quzah
