题解 | #删除有序链表中重复的元素-II#

/**
 * struct ListNode {
 *	int val;
 *	struct ListNode *next;
 * };
 */
/**
 * 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
 *
 * 
 * @param head ListNode类 
 * @return ListNode类
 */
struct ListNode* deleteDuplicates(struct ListNode* head ) {
    // write code here
    if(head == NULL || head->next == NULL) return head;
    struct ListNode* headL = (struct ListNode*)malloc(sizeof(struct ListNode));
    headL->next = head;
    struct ListNode* ph , *c1 , *c2;
    ph = headL;
    c1 = head;
    int i = 0;
    while(c1){
        c2 = c1->next;
        while(c2 && c1->val == c2->val) c2 = c2->next , i++;
        if(i > 0){
            ph->next = c2;
            c1 = c2;
            i = 0;
        }
        else{
            ph = c1;
            c1 = c2;
        }
    }
    return headL->next;
}