January 14, 2021

```
Given the head of a sorted linked list, delete all duplicates such that each element appears only once. Return the linked list sorted as well.
Input: head = [1,1,2,3,3]
Output: [1,2,3]
```

```
The number of nodes in the list is in the range [0, 300].
-100 <= Node.val <= 100
The list is guaranteed to be sorted in ascending order.
```

```
/**
* Definition for singly-linked list.
* public class ListNode {
* int val;
* ListNode next;
* ListNode() {}
* ListNode(int val) { this.val = val; }
* ListNode(int val, ListNode next) { this.val = val; this.next = next; }
* }
*/
class Solution {
public ListNode deleteDuplicates(ListNode head) {
ListNode current = head;
while(current != null) {
ListNode save = current;
while(save.next != null) {
save = save.next;
if (current.val == save.val) {
current.next = save.next;
}
}
current = current.next;
}
return head;
}
}
```

```
public ListNode deleteDuplicates(ListNode head) {
ListNode current = head;
while (current != null && current.next != null) {
if (current.next.val == current.val) {
current.next = current.next.next;
} else {
current = current.next;
}
}
return head;
}
```

*Source*