数据结构面试题oj练习

题

      

oj 链接：https://leetcode-cn.com/problems/remove-linked-list-elements/description/

/**
 * Definition for singly-linked list.
 * struct ListNode {
 *     int val;
 *     struct ListNode *next;
 * };
 */
struct ListNode* removeElements(struct ListNode* head, int val) {
    
    struct ListNode* pCur = head;
    struct ListNode* pPre = NULL;
    
    while (pCur)
    {
        if (val == pCur->val)
        {
            if(head == pCur)
            {
                head = pCur->next;
                free(pCur);
                pCur = head;
            }
            else
            {
                pPre->next = pCur->next;
                free(pCur);
                pCur = pPre->next;
            }
        }
        else
        {
            pPre = pCur;
            pCur = pCur->next;
        }
    }
    return head;
}