Remove duplicates from sorted List II

Remove duplicates from sorted List II Total accepted: 17137 total submissions: 69046my submissions

Given a sorted Linked List, delete all nodes that have duplicate numbers, leaving only distinct numbers from the original list.

For example,
Given1->2->3->3->4->4->5, Return1->2->5.
Given1->1->1->2->3, Return2->3.

For the classic linked list question, remove all repeated numbers from the sorted linked list. Because the sorted and duplicated numbers are all in one, the duplicate number is deleted when the linked list is scanned, add it to the new linked list without repeating it.

/** * Definition for singly-linked list. * struct ListNode { *     int val; *     ListNode *next; *     ListNode(int x) : val(x), next(NULL) {} * }; */class Solution {public:    ListNode *deleteDuplicates(ListNode *head) {        ListNode *new_head, *curr_node, *next_node, *next2_node, *new_list_tail;        curr_node = head;        new_head = NULL;        bool is_duplicate;        while (curr_node) {            next_node = curr_node->next;            is_duplicate = false;            while (next_node && next_node->val == curr_node->val) {                next2_node = next_node->next;                delete next_node;                next_node = next2_node;                is_duplicate = true;            }            if (is_duplicate) {                delete curr_node;            } else {                if (NULL == new_head) {                    new_head = curr_node;                    new_list_tail = new_head;                } else {                    new_list_tail->next = curr_node;                    new_list_tail = curr_node;                }            }            curr_node = next_node;        }        if (new_head) {            new_list_tail->next = NULL;        }        return new_head;    }};

Remove duplicates from sorted List II