int rand(void)
The rand() function computes a sequence of pseudo-random integers
in the range of 0 to RAND_MAX (as defined by the header
file <stdlib.h>).
The srand() function sets its argument
seed as the seed for a new sequence of pseudo-random
numbers to be returned by rand(). These sequences are repeatable by calling srand() with the same seed value.
If no seed value is provided, the functions are automatically seeded with a value of 1.
In compliance with the C standard, these functions operate on
int arguments. Since the underlying algorithm already
uses 32-bit calculations, this causes a loss of precision. See random() for an alternate set of functions that retains full
32-bit precision.