random numbers in c

[Jennifer H. Zemsky]

sto at Bonnie.ICS.UCI.EDU writes:
>	does anyone know how to generate random numbers in c from X to
>Y , where  X and Y can be postive or negative ?

i assume you want a random integer on the range [X,Y]
this is a routine that i use. it works for me.
this should work for positive and/or negative values of high and low.

if you want non-integers, chagne the value of modsize to high-low
and remove the (int) cast from the return line. snafu: the range
for non-integers is [low,high).

i don't think that you need any extra #include libraries... maybe math.h ?


-----cut---here-----
int Random (low, high)
	int low, high;
{
	int modsize = high-low+1;
	double valu;

	valu = drand48();         /* [0,1) */
	valu *= modsize;          /* [0, modsize)*/
	valu += low;              /* [low, high+1)*/
	return ((int) valu);      /*[low, high]*/
}
-----cut---here-----

--hymie
jhz at cunixa.cc.columbia.edu
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