How can I traverse a 2D array in an alternating order

Question

I am writing a swift application so this question would be best answered in swift or any other language if the logic is the same.

I have a 2D array and I want to iterate through each even row as normal 0 - x however every odd row I would like to iterate in the opposite direction of x - 0.

I haven't included any code as it doesn't seem necessary. Any answers would be appreciated - code would be appreciated but isn't required I need to know the method to achieve this desired functionality.

Answer 1

let array: [[Int]] = [[1, 2, 3], [4, 5, 6], [7, 8, 9]]

for (r, row) in array.enumerated() {
    for p in (r % 2 == 0 ? row : row.reversed()) {
        print(p)
    }
}