LeetCode Problem : Insertion Sort List

Problem

Sort a linked list using insertion sort.

Code

ListNode *insertionSortList(ListNode *head) {
    // IMPORTANT: Please reset any member data you declared, as
    // the same Solution instance will be reused for each test case.
    if(!head)
        return 0;
    ListNode *node = head;
    while(node->next){
        if(node->next->val < head->val){
            ListNode *tmp = node->next;
            node->next = tmp->next;
            tmp->next = head;
            head = tmp;
        }
        else{
            ListNode *pos = head;
            while(pos != node && node->next->val > pos->next->val)
                pos = pos->next;
            if(pos == node)
                node = node->next;
            else{
                ListNode *tmp = pos->next;
                pos->next = node->next;
                node->next = node->next->next;
                pos->next->next = tmp;
            }
        }
    }
    return head;
}