博文中会简要介绍Leetcode P0203题目分析及解题思路。
“Remove Linked List Elements”是一道非常基础的链表问题，主要考察的就是链表的删除操作。这里就不再赘述具体方法，相信大家都十分了解了。
Remove all elements from a linked list of integers that have value val.
Example:
Input: 1->2->6->3->4->5->6, val = 6 Output: 1->2->3->4->5
以下是Java的题解代码实现。
/**
* Definition for singly-linked list.
* public class ListNode {
* int val;
* ListNode next;
* ListNode() {}
* ListNode(int val) { this.val = val; }
* ListNode(int val, ListNode next) { this.val = val; this.next = next; }
* }
*/
class Solution {
public ListNode removeElements(ListNode head, int val) {
ListNode dummy = new ListNode(0, head);
ListNode prev = dummy, curr = head;
while (curr != null) {
if (curr.val == val)
prev.next = curr.next;
else
prev = curr;
curr = curr.next;
}
return dummy.next;
}
}
以下是C++的题解代码实现。
/**
* Definition for singly-linked list.
* struct ListNode {
* int val;
* ListNode *next;
* ListNode() : val(0), next(nullptr) {}
* ListNode(int x) : val(x), next(nullptr) {}
* ListNode(int x, ListNode *next) : val(x), next(next) {}
* };
*/
class Solution {
public:
ListNode* removeElements(ListNode* head, int val) {
ListNode *dummy = new ListNode(0, head);
ListNode *prev = dummy, *curr = head;
while (curr) {
if (curr->val == val) {
prev->next = curr->next;
}
else {
prev = curr;
}
curr = curr->next;
}
return dummy->next;
}
};