Suppose you have a function (or a magic ball) that is capable of producing a totally random integer between 1 and 5 (inclusive).

Using this, how would you generate a random number (also an integer) between 1 and 7 (inclusive)? (Note that the for the number to be random, all integers between 1 and 7 must have an equal chance of being generated)

Assume that using your 1-5 generator is pretty time-consuming, so you want to minimize the number of times you are going to use it.

(In reply to re: solution by Gamer)

My assumption was that this random number generator (of integers between 1 and 7) would be called several times, not just once. I see that that's not stated in the problem, but I guess I just didn't (don't) see a need for just one random number, but rather some stochastic trials that need integers from 1 - 7.

But yes, if you need only one random number, choosing just two integers from 1-5 and using fl's techniques would be superior.

Posted by Charlie on 2003-06-30 15:14:41