/**
 *
 * Ashish Patel
 * e: ashishsushilPatel@gmail.com
 * w: https://ashish.me
 *
 */

/* 
 * Given a sorted linked list, delete all duplicates such that each element appear only once.
 * 
 * Example 1:
 * 
 * Input: 1->1->2
 * Output: 1->2
*/

function ListNode(val) {
  this.val = val
  this.next = null
}

function removeDuplicatesFromSortedList(head) {
  let current = head
  while (current && current.next) {
    if (current.val === current.next.val) {
      current.next = current.next.next
    } else {
      current = current.next
    }
  }
  return head
}

test('remove Duplicates From Sorted List', () => {
  const ll1 = new ListNode(1)
  ll1.next = new ListNode(1)
  ll1.next.next = new ListNode(2)

  const ll2 = new ListNode(1)
  ll2.next = new ListNode(2)
  expect(removeDuplicatesFromSortedList(ll1)).toEqual(ll2)
})