Book book[1000];//定义图书存储空间
int count = 0;
bool tag = true;
while (tag) {
cout << "请输入书号，书名和价格(中间以空格符隔开)，以0 0 0结束" << endl;
cin >> book[count].no;
cin >> book[count].name;
cin >> book[count].price;
if (book[count].no == 0 && book[count].name == 0 && book[count].price == 0) { tag = false; }
count++;
if (count == M) { tag = false; }
}
book[count].name 应该是一个字符数组吧，不能直接book[count].name == 0
改成：
strcmp(book[count].name,"0") == 0