147. Insertion Sort List

Sort a linked list using insertion sort. 

需要再考虑！

/** * Definition for singly-linked list. * struct ListNode { *     int val; *     ListNode *next; *     ListNode(int x) : val(x), next(NULL) {} * }; */ //每次循环新链表找到新结点将要插入的位置class Solution {public:    ListNode* insertionSortList(ListNode* head) {        ListNode* sortHead = new ListNode(-1);        ListNode* cur = head;        while(cur)        {           ListNode* p = sortHead;           ListNode *pnext = cur->next;            while(p && p->next && p->next->val < cur->val)           {               p = p->next;           }           cur->next = p->next;           p->next = cur;             cur = pnext;          }              return sortHead->next;      }};