remove-duplicates-from-sorted-list.java

// 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.
//
//


/**
 * Definition for singly-linked list.
 * public class ListNode {
 *     int val;
 *     ListNode next;
 *     ListNode(int x) { val = x; }
 * }
 */
class Solution {
    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;
    }
}