在二维数组 NxN Swift 上创建、随机填充和搜索元素

Question

我创建了一个数字数组，尝试填写它们的规则或随机大小 NxN，然后查找每个对角线中的数量并推导出它。帮助理解我在 cmets 中指出的错误。我究竟做错了什么？谢谢！

func diagonals (n:Int) -> String{
        var sumFirst: Int
        var sumSecond: Int

        var multArray = Array(count: n, repeatedValue: Array(count: n, repeatedValue: 0))
                print(multArray) //create 2d array NxN with Initialisation

        for var i in multArray {
            for var k in multArray {
                multArray[i][k] = i+k // fill array elements the sum of the indices (error line) or we can fill it random, but how?
                if i==k { //check element on the main diagonal
                     sumFirst += multArray[i][k]  // do sum (error line)
                }
                if (i+k) == n  { //check element on secondary diagonal (error line)
                    sumSecond += multArray[i][k] // do sum (error line)
                }
            }
        }

        return "Sum elemets on main diagonal =\(sumFirst) and second =\(sumSecond)"
    }

    diagonals(3)

Answer 1

解决了！

    func diagonals (n:Int) -> String{
    var sumFirst = 0
    var sumSecond = 0

    var multArray = Array(count: n, repeatedValue: Array(count: n, repeatedValue: 0))
            print(multArray) //create 2d array NxN with Initialisation

    for indexI in multArray.indices {
        for indexK in multArray.indices {
            multArray[indexI][indexK] = Int(arc4random_uniform(UInt32(n))) // fill array elements randomly
            if indexI==indexK { //check element on the main diagonal
                 sumFirst += multArray[indexI][indexK]  // do sum
            }
            if (indexI+indexK + 1) == n  { //check element on secondary diagonal
                sumSecond += multArray[indexI][indexK] // do sum
            }
        }
    }
print(multArray)
    return "Sum elemets on main diagonal =\(sumFirst) and second =\(sumSecond)"
}

diagonals(3)