总结、思考、实践，反思，再实践、再反思。
链表逆序
普通循环：
typedef struct _tagmyNode { int data; struct _tagmyNode* next; } Node ,*Nodeptr; Nodeptr resL(Nodeptr head) { if(head == NULL || head->next ==NULL)return head; Nodeptr p1 = head, p2 = p1->next; p3 = p2->next; p1->next = 0; //loop while(p2) { p2->next = p1; p1 = p2; p2 = p3; p3 = p3->next; } //loop end p2->next = p1; head = p2; return head; }
递归循环：
