链表不能显示结果，，，
//films2.c 使用结构链表#include <stdio.h>#include <stdlib.h> //提供malloc()原型#include <string.h> //提供strcpy()原型#define TSIZE 45 //存放片名的数组大小struct film{ char title[TSIZE]; int rating; struct film * next; //指向链表的下一个结构};int main(void){ struct film * head = NULL; //初始化头指针 struct film * prev, * current; char input[TSIZE]; //收集并存储信息 puts("Enter first movie title: "); while(gets(input) != NULL && input[0] != '\0') { current = (struct film *) malloc(sizeof(struct film)); if (head = NULL) //第一个结构 head = current; else //后续结构 prev->next = current; current->next = NULL; strcpy(current->title,input); puts("Enter your rating <0-10>: "); scanf("%d",¤t->rating); while(getchar() != '\n') continue; puts("Enter next movie title (empty line to stop): "); prev = current; } //给出电影列表 if(head = NULL) printf("No data entered. "); else printf("Here is the movie list: \n"); current = head; while(current != NULL) { printf("Movie: %s Rating: %d\n",current->title,current->rating); current = current->next; } //任务已完成，因此释放所分配的内存 current = head; while(current != NULL) { free(current); current = current->next; } printf("Bye!\n"); return 0;}if(head = NULL)