正序记录到数组中，然后原地反转数组即可

func printListReversingly(head *ListNode) []int {
    var h []int
    for head != nil {
        h = append(h, head.Val)
        head = head.Next
    }
    for i, j:=0, len(h)-1; i<j; i, j = i+1, j-1 {
        h[i], h[j] = h[j], h[i]
    }
    return h
}