LeetCode: Remove Duplicates from Sorted List Solution

Approach

Keep jump over next node until values are not equal

Implementation

1var deleteDuplicates = function (head) {
2  let node = head
3
4  while (node) {
5    while (node.next && node.val === node.next.val) {
6      node.next = node.next.next
7    }
8    node = node.next
9  }
10
11  return head
12}

Implementation (recursive)

Note the recursive solution

• it would be less painful to understand if we draw it down
• one thing to remember, return statement of first call will run last

1var deleteDuplicates = function (head) {
2  if (!head) return null
3  head.next = deleteDuplicates(head.next)
4  return head.next && head.next.val === head.val ? head.next : head
5}