How can I generate a random number within a range but exclude some?

Question

How can I generate a random number within a range but exclude some, without keep generating and checking if the generated number is one of those that I want to exclude?

Answer 1

Depending on how large the list of random numbers you're excluding, I would just generate your numbers and check if it's in the array of excluded numbers- if it is, just discard it. I know you don't want to check every time, but I can't think of another way besides specifying the ranges explicitly and if you have more than 5 numbers you're excluding that might be a bit worse.