【leetcode】Insertion Sort List

Sort a linked list using insertion sort.

 

class Solution {
public:
    ListNode* insertionSortList(ListNode* head) {
        ListNode *newhead=new ListNode(-1);
        while(head!=NULL)
        {
            //保存head位置
            ListNode *tmp=head->next;
            ListNode *cur=newhead;

            while(cur->next!=NULL&&cur->next->val<head->val)
            {
                cur=cur->next;
            }
            //插入
            head->next=cur->next;
            cur->next=head;
            //恢复head
            head=tmp;
        }

        return newhead->next;
    }
};