Remove Linked List Elements

Description

Remove all elements from a linked list of integers that have value val.

Example
Given 1->2->3->3->4->5->3, val = 3, 
you should return the list as 1->2->4->5

Link

Lintcode_ladder

Method

1. x
2. x

Example

1. 1

/**
 * Definition for singly-linked list.
 * struct ListNode {
 *     int val;
 *     ListNode *next;
 *     ListNode(int x) : val(x), next(NULL) {}
 * };
 */
class Solution {
public:
    /**
     * @param head a ListNode
     * @param val an integer
     * @return a ListNode
     */
    ListNode *removeElements(ListNode *head, int val) {
        // Write your code here
        if (!head) {
            return nullptr;
        }
        ListNode dummy(0);
        dummy.next = head;
        ListNode* prev = &dummy;
        while (prev->next) {
            if (prev->next->val != val) {
                prev = prev->next;
                continue;
            }
            ListNode* tmp = prev->next;
            prev->next = prev->next->next;
            delete tmp;
        }
        return dummy.next;
    }
};

Similar problems

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