我正在尝试将斐波那契数放入一个数组中,并希望在 playground 控制台中查看数组输出,但由于某种原因我没有看到任何输出。有人可以帮助我理解我在程序中犯的错误吗?
import UIKit
class FibonacciSequence {
let includesZero: Bool
let values: [Int]
init(maxNumber: Int, includesZero: Bool) {
self.includesZero = includesZero
values = [0]
var counter: Int
if (includesZero == true) { counter = 0 }
else { counter = 1 }
for counter <= maxNumber; {
if ( counter == 0 ) {
values.append(0)
counter = 1
}
else {
counter = counter + counter
values.append(counter)
}
}
println(values)
}
println(values)
return values
}
let fibanocciSequence = FibonacciSequence(maxNumber:123, includesZero: true)
最佳答案
@ABakerSmith 已按原样为您提供了代码中问题的简要概述,但您可能还想考虑编写 SequenceType
来代替初始化数组成员变量的类返回斐波那契数:
struct FibonacciSequence: SequenceType {
let maxNumber: Int
let includesZero: Bool
func generate() -> GeneratorOf<Int> {
var (i, j) = includesZero ? (0,1) : (1,1)
return GeneratorOf {
(i, j) = (j, i+j)
return (i < self.maxNumber) ? i : nil
}
}
}
let seq = FibonacciSequence(maxNumber: 20, includesZero: false)
// no arrays were harmed in the generation of this for loop
for num in seq {
println(num)
}
// if you want it in array form:
let array = Array(seq)
如果你想提高多代的性能,你当然可以记住序列。
关于ios - Swift Playground 没有输出,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/29753278/