[数据结构与算法]LeetCode 第82题

LeetCode 第82题

直接上代码

/**
 * 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 nextNode = head;
        if(null == head) {
            return head;
        }
        ListNode tempNode = head.next;
        if(null == tempNode) {
            return head;
        }
        boolean flag = false;
		while(tempNode != null && nextNode.val == tempNode.val) {
            tempNode = tempNode.next;
            flag = true;
        }
        nextNode.next = tempNode;
        boolean count = false;
        while(tempNode != null && tempNode.next != null) {
		if(tempNode.val == tempNode.next.val) {
                tempNode = tempNode.next;
                count = true;
            }else {
                if(count) {
                    nextNode.next = tempNode.next;
                    tempNode = tempNode.next;
                    count = false;
                }else {
                    nextNode = tempNode;
                    tempNode = tempNode.next;
                }
            }
        }
        if(count) {
                    nextNode.next = tempNode.next;
                    tempNode = tempNode.next;
                }
		if(flag) {
            return head.next;
        }
        return head;
    }
}

这个一开始想用两个指针指向遍历的节点，后来发现越写越复杂，感觉不对。改成了只用一个指针指向遍历的节点
只遍历了一次链表