NEED HELP: random numbers

[helpme]

rand() generates a random number with equal probability i believe right?
how can I generate uniform random variable [0, 1] values with different probabilites?

example: probability p=0.9 being true(value being 1) and p=0.1 being false(value being 0)

[Alvaro]

What you are asking for is not a uniform random variable. You want a biased coin (a.k.a. Bernoulli distribution).

Code: Select all

double uniform(void){
   return (double)std::rand()/RAND_MAX;
}

int bernoulli(double p){
   return uniform()<p;
}