LeetCode-83:Remove Duplicates from Sorted List

原题描述如下:

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

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

题意：判去除单链表里的所有重复数字。

解题思路：设置一个头结点指针，不断与它的next指针比较，若相等，则将其next删除。

Java代码：

/**
 * Definition for singly-linked list.
 * public 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 ln = head;
        
        while(ln.next != null){
            if(ln.val == ln.next.val){
                ln.next = ln.next.next;
            }else{
                ln = ln.next;
            }
        }
        
        return head; 
    }
}