Bernoulli distribution simulation

bernoulli.c

/*
 * bernoulli.c
 *
 * Bernoulli distribution simulation
 */

#include <stdio.h>
#include <stdlib.h>
#include <assert.h>

int main(int argc, char ** argv)
{
        double p;
        assert(argc == 2);
        assert(sscanf(argv[1], "%lf", &p) == 1);
        assert(p != 0);
        srand (time(NULL));
        double r = (double) rand() / (double) RAND_MAX;
        if (r <= 1 - p)
                puts("HEADS");        
        else
                puts("TAILS");
        return 0;
}