Shulou(Shulou.com)06/02 Report--

This article shows you how to delete the repeated elements in the sorted list in LeetCode. The content is concise and easy to understand, which will definitely brighten your eyes. I hope you can get something through the detailed introduction of this article.

Description of the topic

Given a sorted linked list, delete all duplicate elements so that each element appears only once.

Example 1:

Input: 1-> 1-> 2 output: 1-> 2

Example 2:

Input: 1-> 1-> 2-> 3-> 3 output: 1-> 2-> 3.

This question examines the basic pointer operation of the linked list, as long as you find the node pointer to be deleted while traversing the linked list, and then delete it, as follows:

Iterate through the copy of the header node current of the linked list until each traversal of the last node determines whether the current node value is equal to the next node value. If so, delete the next node. If not, continue traversing the next node and finally return to the chain header node class Solution {

Public:

ListNode* deleteDuplicates (ListNode* head) {

/ / 0. Empty linked list returns nullptr

If (head = = nullptr)

Return nullptr

/ / 1. No head pointer operation, the head pointer is used to return the result

ListNode * cur = head

ListNode * del_node = nullptr

While (current- > next! = nullptr) {

/ / 2. Find a node with the same element

If (cur- > val = = cur- > next- > val) {

/ / 3. Save the node to be deleted

Del_node = cur- > next

/ / 4. Disconnect del_node nod

Cur- > next = del_node- > next

/ / 5. Delete nod

Delete del_node

/ / 6. Programming specification: prevent the occurrence of wild pointers

Del_node = nullptr

} else {

/ / 7. Continue to traverse backwards without finding the same element

Cur = cur- > next

}

}

Return head

}

}

Complexity analysis time complexity: O (n), only need to traverse n linked list nodes at a time space complexity: O (1), only use constant memory pointer units

The above is how to delete the repeated elements in the sorted list in LeetCode. Have you learned the knowledge or skills? If you want to learn more skills or enrich your knowledge reserve, you are welcome to follow the industry information channel.

Welcome to subscribe "Shulou Technology Information " to get latest news, interesting things and hot topics in the IT industry, and controls the hottest and latest Internet news, technology news and IT industry trends.