changing probability of getting a random number

Question

I would like to generate a random number between 0 and 3 and I have the following in my code:

int random = rand() % 4;

This works fine but

Answer 1

You didn't give exact proportions, but suppose you want 1, 2, and 3 to each occur 32% of the time, and 0 to occur the other 4%. Then you could write:

int random = rand() % 25;
if(random > 0)
    random = random % 3 + 1;

(Obviously you'd need to adjust that for different proportions. And the above is just one approach; many similar approaches could work.)