2019-10-29 移除链表元素

删除链表中等于给定值 val 的所有节点。

示例:

输入: 1->2->6->3->4->5->6, val = 6
输出: 1->2->3->4->5

C++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* h = new ListNode(0);
        h->next = head;
        if(!head){
            return NULL;
        }
        while(h->next&&h->next->val == val){
            head = h->next->next;
            h->next = head;
        }
        while(h&&h->next){
            if(h->next->val == val){
                h->next = h->next->next;
            }else{
                h = h->next;
            }
        }
        return head;
    }
};