Remove Duplicates from Sorted List
<p>Given the <code>head</code> of a sorted linked list, <em>delete all duplicates such that each element appears only once</em>. Return <em>the linked list <strong>sorted</strong> as well</em>.</p>

<p>&nbsp;</p>
<p><strong class="example">Example 1:</strong></p>
<img alt="" src="https://fastly.jsdelivr.net/gh/doocs/leetcode@main/solution/0000-0099/0083.Remove%20Duplicates%20from%20Sorted%20List/images/list1.jpg" style="width: 302px; height: 242px;" />
<pre>
<strong>Input:</strong> head = [1,1,2]
<strong>Output:</strong> [1,2]
</pre>

<p><strong class="example">Example 2:</strong></p>
<img alt="" src="https://fastly.jsdelivr.net/gh/doocs/leetcode@main/solution/0000-0099/0083.Remove%20Duplicates%20from%20Sorted%20List/images/list2.jpg" style="width: 542px; height: 222px;" />
<pre>
<strong>Input:</strong> head = [1,1,2,3,3]
<strong>Output:</strong> [1,2,3]
</pre>

<p>&nbsp;</p>
<p><strong>Constraints:</strong></p>

<ul>
	<li>The number of nodes in the list is in the range <code>[0, 300]</code>.</li>
	<li><code>-100 &lt;= Node.val &lt;= 100</code></li>
	<li>The list is guaranteed to be <strong>sorted</strong> in ascending order.</li>
</ul>
Linked List
/**
 * 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 cur = head;
        while (cur != null && cur.next != null) {
            if (cur.val == cur.next.val) {
                cur.next = cur.next.next;
            } else {
                cur = cur.next;
            }
        }
        return head;
    }
}