lintcode-452-删除链表中的元素

452-删除链表中的元素

思路

code

/**
* 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 == NULL) {
return head;
}
ListNode * newHead = new ListNode(0);
newHead->next = head;
ListNode * temp = head, *p = newHead, *q = temp->next;
while (temp != NULL && temp->next != NULL) {
if (temp->val == val) {
p->next = q;
delete temp;
}
else {
p = p->next;
}
temp = temp->next;
if (q->next != NULL) {
q = q->next;
}
}
if (temp->next == NULL && temp->val == val) {
p->next = NULL;
}
return newHead->next;
}
};