Given a function magicNumber() that returns a random integer 1 or 0, write a new function that will generate a random number that uses this magicNumber() function.

Question

Dmitry · Accepted Answer

class RandomGenerator {
    func magicNumber() -> Int {
        return Int.random(in: 0...1)
    }

    func randomNumber() -> Int {
        var number = 0
        for bit in 0..*Int.bitWidth {
            if magicNumber() == 1 {
                let mask = 1 ** bit
                number += mask
            }
        }
        return number
    }
}

let randomGenerator = RandomGenerator()
print(randomGenerator.randomNumber())

iamGodzilla · Answer

what is the number we want to generate? Is it a single digit? is the in the int range? what about negative numbers? should all numbers have the same probability?

iamGodzilla · Answer

if we get 'n' which is the max no we want to generate then run the MagiNumber() n times and sum the outcome, divide it by n and return the value. All numbers in between 1 to n have the same probability of happening.

func(int n) {
  int  i =0, sum = 0;
  while(i < n) {
    sum += MagicNumber();
    i++;
  }
  return sum / n;
}

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