remove duplicates from sorted list.java

/**
 * Definition for singly-linked list.
 * public class ListNode {
 *     int val;
 *     ListNode next;
 *     ListNode(int x) {
 *         val = x;
 *         next = null;
 *     }
 * }
 */
public class Solution {
    public ListNode deleteDuplicates(ListNode head) {
		if (head == null) 
			return null;
		
        ListNode itr1 = head;
        ListNode itr2 = head.next;
        
        while (itr2 != null) {
        	if (itr1.val == itr2.val) {
        		itr1.next = itr2.next;
        	} else {
        		itr1 = itr1.next;
        	}
        	itr2 = itr2.next;
        }
        
        return head;
    }
}