83. 删除排序链表中的重复元素
https://leetcode-cn.com/problems/remove-duplicates-from-sorted-list/description/
给定一个排序链表,删除所有重复的元素,使得每个元素只出现一次。
示例 1:
输入: 1->1->2
输出: 1->2
示例 2:
输入: 1->1->2->3->3
输出: 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 head;
}
ListNode* cur = head;
ListNode* next = cur->next;
ListNode* temp = NULL;
while(cur->next){
next = cur->next;
if(cur->val == next->val){
temp = next;
cur->next = next->next;
delete temp;
}
else{
cur = cur->next;
}
}
return head;
}
};
看了下运行时间最快的算法,分析了一下,LeetCode编程都不注意内存回收的嘛,以空间换时间(好像不是一般我们说的空间换时间算法哈。。。),内存泄漏。。。。
/**
* 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 head;
ListNode* pre = head;
ListNode* cur = head->next;
while(cur != NULL){
if(cur->val == pre->val)
pre->next = cur->next;
else
pre = cur;
cur = cur->next;
}
return head;
}
};