LeetCode83 Remove Duplicates from Sorted List

题目：

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

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

分析：

链表去重。还是链表题的主要特点就是考察代码实现，除了个别题，没太多算法。

代码：

/**
 * Definition for singly-linked list.
 * struct ListNode {
 *     int val;
 *     ListNode *next;
 *     ListNode(int x) : val(x), next(NULL) {}
 * };
 */
class Solution {
public:
    ListNode* deleteDuplicates(ListNode* head) {
        ListNode dummy(0);
        dummy.next = head;
        while (head != nullptr && head -> next != nullptr) {
            if (head -> next -> val == head -> val) {
                ListNode* temp = head -> next;
                head -> next = head -> next -> next;
                delete temp;
            }
            else {
                head = head -> next;
            }
        }
        return dummy.next;
    }
};