LeetCode問題解(199):Remove Linked List Elements

タイトル:
Remove all elements from a linked list of integers that have value val.
Example Given: 1 --> 2 --> 6 --> 3 --> 4 --> 5 --> 6, val = 6 Return: 1 --> 2 --> 3 --> 4 --> 5
問題:
C++版:

class Solution {
public:
    ListNode* removeElements(ListNode* head, int val) {
        if(head == NULL)
            return NULL;
        
        ListNode* dummy = new ListNode(0);
        dummy->next = head;
        ListNode* p = dummy;
        while(p && p->next) {
            if(p->next->val == val) {
                p->next = p->next->next;
                continue;
            }
            p = p->next;
        }
        return dummy->next;
    }
};

Java版:

public class Solution {
    public ListNode removeElements(ListNode head, int val) {
        if(head == null)
            return null;
        ListNode dummy = new ListNode(0);
        dummy.next = head;
        ListNode p = dummy;
        while(p != null && p.next !=null) {
            if(p.next.val == val) {
                p.next = p.next.next;
                continue;
            }
            p = p.next;
        }
        return dummy.next;
    }
}

Python版:

class Solution(object):
    def removeElements(self, head, val):
        """
        :type head: ListNode
        :type val: int
        :rtype: ListNode
        """
        if head == None:
            return None
            
        dummy = ListNode(0)
        dummy.next = head
        p = dummy
        while p != None and p.next != None:
            if p.next.val == val:
                p.next = p.next.next
                continue
            p = p.next
        return dummy.next