Insertion Sort List -- leetcode

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) {} * }; */class Solution {public:    ListNode* insertionSortList(ListNode* head) {        ListNode fake(0);        while (head) {            ListNode *runner = &fake;            while (runner->next && runner->next->val < head->val)                runner = runner->next;                        ListNode *bak = head->next;            head->next = runner->next;            runner->next = head;            head = bak;        }        return fake.next;    }};