冒泡排序

 /* Definition for singly-linked list.
 * struct ListNode {
 *     int val;
 *     struct ListNode *next;
 * };
 */
 
 
struct ListNode* mergeTwoLists(struct ListNode* list1, struct ListNode* list2){
    if(list1==NULL) return list2;
    if(list2==NULL) return list1;
 
    struct ListNode* temp=list1;
    while(temp->next!=NULL)
    {
        temp=temp->next;
    }
    temp->next = list2;
    for(struct ListNode* trun = list1; trun->next != NULL; trun=trun->next)
    {
        for(struct ListNode* move = list1; move->next != NULL; move = move->next)
        {
            
            if(move->val > move->next->val)
            {
                int temp2=move->val;
                move->val = move->next->val;
                move->next->val=temp2;
                   
            }
                
            
        }
    }
 
 
    
    return list1;
        
}

如图

仅仅交换结点内的数值而非交换节点，关键还在于for循环次数。