如何使用递归在 Swift Playground 中打印斐波那契数列

Question

我正在尝试在 Swift 中使用递归来打印出 "n" 次迭代的斐波那契数列。但是，我一直收到同样的错误。

我已经尝试过不使用递归并且能够做到。但是，我现在正尝试通过使用递归以更复杂和 "computer scientisty" 的方式来做。

func fibonacciSequence (n: Int) -> [Int]  {

// Consumes a number "n", which is the number of iterations to go through with the Fibonacci formula and prints such sequence.

    var fibonacciArray = [Int]()

    for n in 0 ... n {

        if n == 0 {
            fibonacciArray.append(0)
        }
        else if n == 1 {
            fibonacciArray.append(1)
        }
        else {
            fibonacciArray.append (fibonacciSequence(n: (n - 1)) +
            fibonacciSequence(n: (n-2)))
        }
    }
    return fibonacciArray

我希望用数字 n 调用该函数，并希望该函数打印出斐波那契数列。示例：如果 n = 5，我希望控制台打印 0、1、1、2、3、5。我得到的错误是：（无法将类型 '[Int]' 的值转换为预期的参数类型 'Int').

Answer 1

如上所述，return 值在求和时会导致错误。修复代码的一种可能方法（但不是递归的）是简单地更改 else 语句：

func fibonacciSequence (n: Int) -> [Int]  {

    // Consumes a number "n", which is the number of iterations to go through with the Fibonacci formula and prints such sequence.

    var fibonacciArray = [Int]()

    for n in 0 ... n {

        if n == 0 {
            fibonacciArray.append(0)
        }
        else if n == 1 {
            fibonacciArray.append(1)
        }
        else {
            fibonacciArray.append (fibonacciArray[n-1] + fibonacciArray[n-2] )
        }
    }
    return fibonacciArray
}

递归解决方案如下：


func fibonacciSequence (n: Int, sumOne: Int, sumTwo: Int, counter: Int, start: Bool) {

    if start {
        print(0)
        print(1)
    }
    if counter == -1 {
        print(1)
    }
    if (counter == n - 2) {
        return
    }
    let sum = sumOne + sumTwo
    print(sum)

    fibonacciSequence(n: n, sumOne: sumTwo , sumTwo: sum, counter: counter + 1, start: false)
}

fibonacciSequence(n: 8, sumOne: 0, sumTwo: 1, counter: 0, start: true)

可能有一个 "nicer" 方法，但我希望它能有所帮助。干杯。

Answer 2

fabonacci的递归方式->解法

func fibo( n: Int) -> Int {

        guard n > 1 else { return n }

        return fibo(n: n-1) + fibo(n: n-2)
}

Answer 3

这些是我在 swift 5 playground

中斐波那契数列的解决方案

func fibonacci(n: Int) {
    var num1 = 0
    var num2 = 1
    var nextNum = Int()
    let i = 1
    var array = [Int]()
    array.append(num1)
    array.append(num2)

    for _ in i...n {
       nextNum = num1 + num2
       num1 = num2
       num2 = nextNum
       array.append(num2)
       print(array)
    }

   print("result = \(num2)")
 }

打印（斐波那契（n:5））

Answer 4

    let fibonacci = sequence(state: (0, 1)) {(state: inout (Int, Int)) -> Int? in
        defer { state = (state.1, state.0 + state.1) }
        return state.0
    }
    
    //limit 10
    for number in fibonacci.prefix(10) {
        print(number)
    }

Answer 5

// 标记：- 函数

func fibonacciSeries(_ num1 : Int,_ num2 : Int,_ term : Int,_ termCount : Int) -> Void{
        if termCount != term{
            print(num1)
            fibonacciSeries(num2, num2+num1, term, termCount + 1)
        }
    }

// MARK: - 调用函数 fibonacciSeries(0, 1, 5, 0)

// MARK: - 输出 Put 0 1 1 2 3

注意只需要更改斐波那契数列的项数。

Answer 6

func fibonacci(n: Int) {
    var seq: [Int] = n == 0 ? [0] : [0, 1]
    var curNum = 2
    while curNum < n{
        seq.append(seq[curNum - 1] + seq[curNum - 2])
        curNum += 1 }
    print(seq) }

如何使用递归在 Swift Playground 中打印斐波那契数列

How to print the Fibonacci sequence in Swift Playground using recursion

recursion

fibonacci

swift