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.
思路:定义两个指针,p = head, q = head->next,若p->val == q->val,则指针q一直向后遍历,否则p->next = q ,重复上述操作,直至遍历到链表结尾。
C++代码实现:
/**
* 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 *p = head;
while(p != NULL){
ListNode *q = p->next;
while(q != NULL && p->val == q->val){
q = q->next;
}
p->next = q;
p = p->next;
}
return head;
}
};