LeetCode 82. Remove Duplicate Elements in Sorted List II

原题网址：https://leetcode.cn/problems/remove-duplicates-from-sorted-list-ii/

链表删除元素,如果有重复的,The number will be removed as a whole.

当前节点,Find the first node with a different value from the back;if it follows,说明数字没有重复;Otherwise delete the whole number

    // 注意,这里的删除,Not removing duplicate values,but as long as the numbers are repeated,then this number needs to be removed
    public ListNode deleteDuplicates(ListNode head) {
    
 
        ListNode dummyHead = new ListNode(-1);
        dummyHead.next = head;

        ListNode node = dummyHead;
		// Because it is to delete the whole,So from the previous node you want to keep,就是node.next
        while(node.next != null) {
    
            ListNode cur = node.next;
            ListNode next = cur.next;
            // Find the first node with a distinct value
            while(next!=null && next.val == cur.val) {
    
                next = next.next;
            }
            // If just behind this node,说明没有重复值,Otherwise, delete these duplicate nodes
            if(cur.next != next) {
    
                node.next = next;
            } else {
    
                node = node.next;
            }
        }
        return dummyHead.next;
   
    }

same topic：https://blog.csdn.net/qq_34501351/article/details/126187912?spm=1001.2014.3001.5501

One is to remove duplicate,One is to delete the whole.

keep one,So you can do without virtual nodes,用cur遍历,删除后面的;
整体删除;to get the previous node,So have virtual nodes,用node.next作为条件判断;