Isaac Tonyloi

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# Remove Duplicates from Sorted Linked List

## 83. Remove Duplicates from Sorted List

### Easy

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.

Example 1:

```Input: head = [1,1,2]
Output: [1,2]
```

Example 2:

```Input: head = [1,1,2,3,3]
Output: [1,2,3]
```

Constraints:

• 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.

Python solution

``````# Definition for singly-linked list.
class ListNode:
def __init__(self, val=0, next=None):
self.val = val
self.next = next
class Solution:
def deleteDuplicates(self, head: Optional[ListNode]) -> Optional[ListNode]:

return None

while current.next:
if current.val == current.next.val:
next_element = current.next.next
current.next = next_element
else:
current = current.next

#end

``````

The time complexity of the above solution is O(n), where n is the total number of nodes in the linked list.