链表插入排序

Sort a linked list using insertion sort.

排序一个list使用插入排序的方法

问题解决:

classSolution {

public:

    ListNode *insertionSortList(ListNode *head) {

        if(!head || !head->next)return head;

        ListNode dummyHead(0), *p;

        dummyHead.next = insertionSortList(head->next);

        p = &dummyHead;

         

        while(p && p->next && head->val > p->next->val){

            p = p->next;

        }

        head->next = p->next;

        p->next = head;

         

        returndummyHead.next;

    }

};