Hot to calculate the size of memory to assign given processId and block size in c

Question

I am trying to program a best fit algorithm for assigning a process a size of memory when the method has been given an argument of how much to allocate and the process size, I only know of applying the algorithm when the arguments are arrays. Here is the code

int HowMuchToAllocate(int size, int processId){
//return an integer size to assign the process
}

That is where I am experiencing a problem, Thank You.

Answer 1

Hello Timothy,
AFAIK a program (at runtime) can and will request additional resources as it finds necessary, and system (O/S) decides whether the request was to be granted or not. How do we know how much memory a program needs from outside the program itself?