Leetcode #832: Flipping an Image

func flipAndInvertImage(_ A: [[Int]]) -> [[Int]] {
    var A = A
    for i in stride(from: 0, to: A.count, by: 1) {
        var left = 0
        var right = A[i].count - 1
        while left < right {
            A[i].swapAt(left, right)
            A[i][left] ^= 1
            A[i][right] ^= 1
            left += 1
            right -= 1
        }
        if left == right {
            A[i][left] ^= 1
        }
    }
    return A
}