LeetCode Remove Duplicates from Sorted List

class Solution {
public:
    ListNode *deleteDuplicates(ListNode *head) {
        if (head == NULL) return NULL;
        ListNode *pre, *cur, *tmp;
        pre = head;
        cur = head->next;
        while (cur != NULL) {
            if (pre->val == cur->val) { // dup found
                tmp = cur;
                cur = tmp->next;
                pre->next = tmp->next;
                delete tmp;
            } else {
                pre = cur;
                cur = pre->next;
            }
        }
        return head;
    }
};

水一发

第二轮：

Given a sorted linked list, delete all duplicates such that each element appear only once.

For example,
Given 1->1->2, return 1->2.
Given 1->1->2->3->3, return 1->2->3.

/**
 * Definition for singly-linked list.
 * struct ListNode {
 *     int val;
 *     ListNode *next;
 *     ListNode(int x) : val(x), next(NULL) {}
 * };
 */
 // 9:54
class Solution {
public:
    ListNode *deleteDuplicates(ListNode *head) {
        if (head == NULL) {
            return NULL;
        }
        ListNode* last = head;
        ListNode* cur = head->next;
        ListNode* pre = head;
        while (cur != NULL) {
            if (cur->val != pre->val) {
                last->next = cur;
                last = cur;
            }
            pre = cur;
            cur = cur->next;
        }
        last->next = NULL;
        return head;
    }
};

 对比了一下原来还有delete