如何交错两个数组？

Question

如果我有两个数组，例如

let one = [1,3,5]
let two = [2,4,6]

我想以以下模式[one [0]，two [0]，one [1]，two [1]等合并/交织数组。

//prints [1,2,3,4,5,6]
let comibned = mergeFunction(one, two)
print(combined)

什么是实现合并功能的好方法？

func mergeFunction(one: [T], _ two: [T]) -> [T] {
    var mergedArray = [T]()
    //What goes here
    return mergedArray
}

Answer 1

如果两个数组的 长度相同， 那么这可能是一种解决方案：

let one = [1,3,5]
let two = [2,4,6]

let merged = zip(one, two).flatMap { [$0, $1] }

print(merged) // [1, 2, 3, 4, 5, 6]

此处zip()枚举并行的数组，并返回一对对（2元素元组）的序列，每个数组中都有一个元素。flatMap()从每对创建一个2元素数组，并将结果连接起来。

如果数组的 长度 可以 不同， 则可以将较长数组的额外元素附加到结果中：

func mergeFunction<T>(one: [T], _ two: [T]) -> [T] {
    let commonLength = min(one.count, two.count)
    return zip(one, two).flatMap { [$0, $1] } 
           + one.suffixFrom(commonLength)
           + two.suffixFrom(commonLength)
}

Swift 3更新：

func mergeFunction<T>(_ one: [T], _ two: [T]) -> [T] {
    let commonLength = min(one.count, two.count)
    return zip(one, two).flatMap { [$0, $1] } 
           + one.suffix(from: commonLength)
           + two.suffix(from: commonLength)
}