leetcode 83. Remove Duplicates from Sorted List

ゝ一世哀愁。 2022-06-08 02:35 121阅读 0赞

Given a sorted linked list, delete all duplicates such that each element appear only once.

For example,  
Given 1->1->2, return 1->2.  
Given 1->1->2->3->3, return 1->2->3.

这道题很简单，就是取出链表的重复元素，遍历一次即可。

代码如下：

/*class ListNode
    {
         int val;
         ListNode next;
         ListNode(int x) { val = x; }
    }*/
    
    public class Solution 
    {
        public ListNode deleteDuplicates(ListNode head) 
        {
            if(head==null || head.next==null)
                return head;
    
            ListNode fa=head,son=head.next;
            while(son!=null)
            {
                if(son.val==fa.val)
                {
                    fa.next=son.next;
                    son=fa.next;
                }else
                {
                    fa=son;
                    son=son.next;
                }
            }
            return head;
        }
    }

下面是C++的做法

代码如下：

#include <iostream>
    #include <vector>
    
    using namespace std;
    
    /*
    struct ListNode
    {
        int val;
        ListNode *next;
        ListNode(int x) : val(x), next(NULL) {}
    };
    */
    
    class Solution 
    {
    public:
        ListNode* deleteDuplicates(ListNode* h) 
        {
            ListNode* head = new ListNode(-1);
            head->next = h;
    
            ListNode* i = head->next;
            while (i != NULL)
            {
                ListNode* j = i->next;
                while (j != NULL && j->val == i->val)
                    j = j->next;
                i->next = j;
                i = i->next;
            }
            return head->next;
        }
    };