小编典典

如何交错两个数组?

swift

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
}

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2020-07-07

共1个答案

小编典典

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)
}
2020-07-07