Biased Random Number Generator

Question

I am looking for a random number generator that can be biased. For instance, say I want a random number between 1-5, with the probability being:

1: Comes up 20% of t

Answer 1

Best way's probably to just take the normal unbiased random generator then return based on the interval its value falls into.

Just an if statement that gives 1 for 0:0.2, 2 for 0.2:0.3, 3 for 0.3:0.7, 4 for 0.7:0.95 and 5 for 0.95:1. Best to make either the lower or upper limit of the interval inclusive and the other exclusive.

int biasedRandom(){
double i = randomNumber();
if(i<= 0.2){return 1;}
else if(i <= 0.3){return 2;}
else if(i <= 0.7){return 3;}
else if(i <= 0.95){return 4;}
else{return 5;}
}

Something like that.