package main

/**
 * Definition for singly-linked list.
 * type ListNode struct {
 *     Val int
 *     Next *ListNode
 * }
 */
// lots of pits!! [] [1] [1 1 1]
func deleteDuplicates(head *ListNode) *ListNode {
	if head == nil {
		return nil
	}
	if head.Next == nil {
		return head
	}
	curr := head
	for curr != nil && curr.Next != nil {
		if curr.Next.Val == curr.Val {
			curr.Next = curr.Next.Next
		} else {
			curr = curr.Next
		}
	}
	return head
}