Given the head of a sorted linked list, delete all duplicates such that each element appears only once. Return the linked list sorted as well.
Example 1:
Input: head = [1,1,2]
Output: [1,2]
Example 2:
Input: head = [1,1,2,3,3]
Output: [1,2,3]
Constraints:
- The number of nodes in the list is in the range [0, 300].
- -100 <= Node.val <= 100
- The list is guaranteed to be sorted in ascending order.
Solution
/**
* Definition for singly-linked list.
* struct ListNode {
* int val;
* struct ListNode *next;
* };
*/
struct ListNode* deleteDuplicates(struct ListNode* head){
if (head == NULL) return head;
struct ListNode *p = head, *q;
while (p->next != NULL) {
if (p->next->val == p->val) {
q = p->next;
p->next = q->next;
free(q);
} else {
p = p->next;
}
}
return head;
}
这里不用加头节点，像 20220923 - 203. Remove Linked List Elements 移除链表元素 一样操作判断删除重复元素即可。
