Given a sorted linked list, delete all nodes that have duplicate numbers, leaving only distinct numbers from the original list.

For example,

Given 1->2->3->3->4->4->5, return 1->2->5.

Given 1->1->1->2->3, return 2->3.

 

/** * 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) {        ListNode newHead = new ListNode(0);		ListNode currentNode = newHead;		ListNode first = head;		boolean distinct = true;		while(first != null){			if(first.next != null){				if(first.val == first.next.val)					distinct = false;				else{					if(distinct){						currentNode.next = first;						currentNode = currentNode.next;					}					else						distinct = true;				}							}			//the last node			else{				if(distinct){					currentNode.next = first;					currentNode = currentNode.next;				}			}						first = first.next;					}		currentNode.next = null;		newHead = newHead.next;		return newHead;        }}