2015-11-02 Lesson.swift

func isEven(number: Int) -> Bool {
    return number % 2 == 0
}
//isEven(31)

func isDivisible(x: Int, by y: Int) -> Bool {
    return x % y == 0
}
//isDivisible(30, by: 5)

/// DON'T EVER DO THIS BECAUSE THIS IS INEFFICIENT AF
func numberOfDigitsByConvertingToString(x: Int) -> Int {
    return String(x).characters.count
}
//numberOfDigitsByConvertingToString(1100000)

func numberOfDigits(x: Int) -> Int {
    var temporaryValue = x;
    var count = 0
    while temporaryValue != 0 {
        temporaryValue /= 10
        count++
    }
    return count
}
//numberOfDigits(1100000)

func fizzBuzz(fizzAt fizz: Int, buzzAt buzz: Int, max: Int) {
    for count in 1...max {
        if count % (fizz * buzz) == 0 {
            print("FizzBuzz")
        } else if count % fizz == 0 {
            print("Fizz")
        } else if count % buzz == 0 {
            print("Buzz")
        } else {
            print("\(count)")
        }
    }
}

//fizzBuzz(fizzAt: 3, buzzAt: 5, max: 69)

/// This is an interesting method to do it but it's harder to understand.
/// You don't have to worry about it yet, probably no one does something like this in real apps.
/// For 3 and 5 only.
func bitwiseFizzBuzz(max max: Int) {
    var mutatingMask = 0b110000010010010000011000010000
    let messages: [String?] = [ nil, "Fizz", "Buzz", "FizzBuzz" ]
    
    for count in 1...max {
        let index = mutatingMask & 3
        if let message = messages[index] {
            print(message)
        } else {
            print(count)
        }
        mutatingMask = mutatingMask >> 2 | index << 28
    }
}
//bitwiseFizzBuzz(max: 69)