Swift - 声明2d数组包含

时间:2016-07-04 00:24:27

标签: swift multidimensional-array contains arc4random

我想说如果某个2d数组包含“点”格式[Int,Int],那么重新生成随机数,不计算迭代次数。

for _ in 0..<33{
        let j = Int(arc4random_uniform(10))
        let k = Int(arc4random_uniform(10))
        while live.contains(//The point j,k){
        live.append(Array(arrayLiteral: j,k))
            cells[j][k] = true
        }
    }

1 个答案:

答案 0 :(得分:2)

根据我的理解你的问题,你想要生成一个2D点数组,不包括重复,你可以使用CGPoint或定义你自己的Point

struct Point: Equatable {
    let x: Int
    let y: Int
}

func == (lhs: Point, rhs: Point) -> Bool {
    return lhs.x == rhs.x && lhs.y == rhs.y
}

var live: [Point] = []
for _ in 0..<10{

    var candidate = Point(x: Int(arc4random_uniform(10)), y: Int(arc4random_uniform(10)))
    while live.contains(candidate) {
        candidate = Point(x: Int(arc4random_uniform(10)), y: Int(arc4random_uniform(10)))
    }
    live.append(candidate)
}

或者您可以像这样使用元组

var live: [(Int, Int)] = []
for _ in 0..<10{
    var j = Int(arc4random_uniform(10))
    var k = Int(arc4random_uniform(10))
    while live.contains({$0 == (j, k)}) {
        j = Int(arc4random_uniform(10))
        k = Int(arc4random_uniform(10))
    }
    live.append((j,k))
}

根据您的问题大小,构建所有可能值的数组可能更为理想,然后在每次需要新的随机点集时随机播放并获取第一个X元素。您可以进一步优化它,但代码看起来类似于:

var possibleValues: [Point] = []
for x in 0..<5 {
    for y in 0..<5 {
        possibleValues.append(Point(x: x, y: y))
    }
}

func randomPoints(numberOfPoints: Int) -> [Point] {
    // shuffle original array without changing it
    let shuffled = possibleValues.sorted { _ in arc4random_uniform(10) > 5 }
    // take first X elements
    return Array(shuffled[0..<numberOfPoints])
}

randomPoints(numberOfPoints: 10)

您可以进一步优化此解决方案,但需要了解有关数据集的更多信息。希望这有帮助