147. Insertion Sort List（链表的插入排序）

Sort a linked list using insertion sort.

/** * Definition for singly-linked list. * struct ListNode { *     int val; *     ListNode *next; *     ListNode(int x) : val(x), next(NULL) {} * }; */

所以就是在考insertion sort，AC代码：

class Solution {public:    ListNode* insertionSortList(ListNode* head) {        ListNode dummy(0);        ListNode* pre=&dummy;        ListNode* cur=head;        dummy.next=head;        while(cur){            if(cur->next&&cur->next->val<cur->val){                while(pre->next&&pre->next->val<cur->next->val){                    pre=pre->next;                }                ListNode* tmp=pre->next;                pre->next=cur->next;                cur->next=cur->next->next;                pre->next->next=tmp;                pre=&dummy;            }            else{                cur=cur->next;            }        }        return dummy.next;    }};

看了别人的解答。。。。。亲自写还是有点难的。。（我好菜啊QUQ