stevencurtis

func fib (_ n: Int) -> Int {
    guard n > 1 else {return n}
    var a = 0
    var b = 1
    for _ in 2...n {
        let temp = b
        b = a + b
        a = temp
    }
    return b

stevencurtis

func fib (_ n: Int) -> Int {
    guard n > 1 else {return n}
    return fib(n - 1) + fib(n - 2)
}

stevencurtis

func countDown(_ num: Int){
    if (num < 1) {return}
    print (num)
    return countDown(num - 1)
}

stevencurtis

func fact (_ num: Int) -> Int {
    if num == 1 {return 1}
    return num * fact(num - 1)
}

stevencurtis

func fact (_ num : Int) -> Int {
    if num == 1 {return 1}
    var result = 1
    for i in 1...num {
        result = result * i
    }
    return result
}

stevencurtis

func countDown(_ num: Int){
    if (num < 1) {return}
    var number = num
    while number > 0 {
        print (number)
        number -= 1
    }
}

stevencurtis

var cache : [Int] = [0]

func fib (_ num: Int) -> Int {
    guard num > 1 else { return num }
    if (cache.count > num) {
        return cache[num]
    }
    let fibNum = fibRec(num - 1) + fibRec(num - 2)
    cache.append(fibNum)
    return fibNum

stevencurtis

func fib (_ num: Int) -> Int {
    var first = [0, 1]
    return fib(num, &first)
}

func fib(_ num: Int, _ cache: inout [Int]) -> Int {
    if (cache.count > num) {
        return cache[num]
    }
    let fibNum = fib(num - 1, &cache) + fib(num - 2, &cache)

stevencurtis

func fib(_ n: Int) -> Int {
    guard n > 1 else { return n }
    var cache : [Int] = Array(repeating: 0, count: n)
    cache[0] = 0
    cache[1] = 1
    for i in 2..<n {
        cache[i] = cache[i - 1] + cache[i - 2]
    }
    return cache[n - 1] + cache[n - 2]
}

stevencurtis

func fib (_ num: Int) -> Int {
    guard num > 1 else { return num }
    var a = 0
    var b = 1
    var c = 0
    for _ in 2..<num {
        c = a + b
        a = b
        b = c
    }