leetCode(12):Remove Duplicates from Sorted List 分类： leetCode 2015-06-18 15:48 136人阅读 评论(0) 收藏

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.

/**
 * 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) {
        if(head==NULL)
    		return NULL;
    	if(head->next==NULL)
    		return head;
    	ListNode* p=head;
    	int key=p->val;
    	p=p->next;
    	ListNode* q=head;
    	while(p)
    	{
    		if(p->val==key)
    		{
    			ListNode* toBeDeleted=p;
    			q->next=toBeDeleted->next;
    			p=q->next;
    			delete toBeDeleted;
    			toBeDeleted=NULL;
    		}
    		else
    		{
    			key=p->val;
    			p=p->next;
    			q=q->next;
    		}
    	}
    	return head;
        
    }
};