# 203. Remove Linked List Elements

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

# Solution

Approach 1: Scan the list.

# Code (Python)

Approach 1:

# Code (C++)

Approach 1:

/**
 * Definition for singly-linked list.
 * struct ListNode {
 *     int val;
 *     ListNode *next;
 *     ListNode(int x) : val(x), next(NULL) {}
 * };
 */
class Solution {
public:
    ListNode* removeElements(ListNode* head, int val) {
        ListNode dummyHead(0);
        dummyHead.next = head;
        ListNode *prev = &dummyHead;
        for (ListNode *node = head; node != NULL; node = node->next)
        {
            if (node->val == val)
                prev->next = node->next;
            else
                prev = node;
        }
        return dummyHead.next;
    }
};

class Solution {
public:
    ListNode* removeElements(ListNode* head, int val) {
        ListNode dummyHead(0);
        dummyHead.next = head;
        ListNode *node = &dummyHead;
        while (node != NULL)
        {
            if (node->next && node->next->val == val)
                node->next = node->next->next;
            else
                node = node->next;
        }
        return dummyHead.next;
    }
};