[swift] LeetCode 206. Reverse Linked List

Reverse a singly linked list.

func reverseList(_ head: ListNode?) -> ListNode? {
    var stack = [Int](), p = head
    while let t = p {
        stack.append(t.val)
        p = t.next
    }
    p = head
    while let t = p {
        t.val = stack.popLast()!
        p = t.next
    }
    return head
}

func reverseList(_ head: ListNode?) -> ListNode? {

var stack = [Int](), p = head

while let t = p {

stack.append(t.val)

p = t.next

}

p = head

while let t = p {

t.val = stack.popLast()!

p = t.next

}

return head

}