Function reverseList

reverse_linked_list_206/solution.go:8–30

Returns a pointer to a list that is the reverse of the passed head. This function prepends the first n values in the passed list into a new list and returns the new list.

(head *ListNode)

// This function prepends the first n values in the passed list
// into a new list and returns the new list.
func reverseList(head *ListNode) *ListNode {
	if head == nil {
		return nil
	}

	var rev *ListNode
	for head != nil {
		// hold last head
		hold := head
		head = head.Next

		// prepend into rev
		if rev == nil {
			rev = hold
			rev.Next = nil
		} else {
			hold.Next = rev
			rev = hold
		}
	}

	return rev
}

// Reverses the passed list without creating a new list by
// prepending front nodes to the end.