Leetcode 83. Remove Duplicates from Sorted List

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.

---

解题思路：

按照顺序依次比较，遇到duplicate就跳过去。

Linked List 基本概念题

---

 Java code:

1. 

/**
 * 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) {
            return null;
        }
        
        ListNode p1 = head;
        ListNode p2 = head.next; 
        while(p2!= null) {
            if(p1.val == p2.val) {
                p1.next = p2.next;
            }else {
                p1 = p2;
            }
            p2 = p2.next;
        }
        return head;
    }
}

 2. 九章算法答案 2016.01.18

public class Solution {
    public ListNode deleteDuplicates(ListNode head) {
        if(head == null) {
            return null;
        }
        ListNode node = head;
        while(node.next != null) {
            if(node.val == node.next.val) {
                node.next = node.next.next;
            }else {
                node = node.next;
            }
        }
        return head;
    }
}

---

Reference:

1. http://www.jiuzhang.com/solutions/remove-duplicates-from-sorted-list/