1、修改程序清单17.2,使其既能以郑旭又能以逆序显示电影列表。一种方法是修改链表定义使其可以双向遍历;另一种用递归
//双向链表 #include<stdio.h> #include<stdlib.h> #include<string.h> #define TSIZE 45 struct film { char title[TSIZE]; int rating; struct film *prev; struct film *next; }; int main(void) { struct film *head=NULL; struct film *temp,*current; char input[TSIZE]; puts("Enter title:"); while(gets(input)!=NULL&&input[0]!='