p152 对单链表进行插入排序(leetcode 147)

class Solution {
public:
    ListNode* insertionSortList(ListNode* head) 
    {
        if (head == NULL || head->next == NULL) return head;
        ListNode* dummy = new ListNode(0);
        ListNode* p = NULL;
        ListNode* cur = head;
        ListNode* next = NULL;

        while (cur != NULL)
        {
            next = cur->next;
            p = dummy;
            while (p->next != NULL && p->next->val <= cur->val)
                p = p->next;
            cur->next = p->next;
            p->next = cur;
            cur = next;
        }

        return dummy->next;
    }
};

class Solution {
        public ListNode insertionSortList(ListNode head) 
        {
              if(head==null || head.next==null) return head;
              ListNode dummy=new ListNode(0);
              ListNode p=null;
              ListNode cur=head;
              ListNode next=null;
              
              while (cur!=null)
              {
                  next=cur.next;
                  p=dummy;
                  while(p.next!=null && p.next.val<=cur.val)
                      p=p.next;
                  cur.next=p.next;
                  p.next=cur;
                  cur=next;
              }
              
              return dummy.next;
        }
    }