删除链表元素

要求

删除链表中值为val的结点，例如：1->2->3->4->5->NULL,val = 4,返回1->2->3->5->NULL

代码实现

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#include <iostream>
using namespace::std;

struct ListNode {
    int val;
    ListNode *next;
    ListNode(int x) : val(x), next(NULL) {}
};

class Solution {
public:
    ListNode* removeElements(ListNode* head, int val) {
        if (head==NULL) {
            return head;
        }else{
            ListNode* newHead = new ListNode(0);
            newHead->next = head;
            ListNode* pre = newHead;
            ListNode* p = newHead->next;
            while (p!=NULL) {
                if (p->val == val) {
                    pre->next = p->next;
                    p = p->next;

                }else{
                    pre = pre->next;
                    p = p->next;
                }
            }
            return newHead->next;
        }
    }
};

int main(int argc, const char * argv[]) {

    return 0;
}

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