C++容器 第7选项的排序功能 我思路：对list容器进行一个自定义排序规则进行排序后，然后将排序后的内容写入文件。现在我的排序出了问题，但思路没错，有点搞不懂哪里错了 就是我该怎么改才可以使用自定义排序？
#include<iostream>
using namespace std;
#include<fstream>
#define filename "booklist.txt"
#include<list>
#include<cstring>
#include<iomanip>
class Book
{
public:
Book(string na = " ", int p = 0, int n = 0, string m = " ", string o = " ", int s = 0, int r = 0, string t = " ")
{
name = na;
num = n;
riqi = p;
chubanshe = m;
leibie = o;
bianhao = s;
ISBN = r;
zuozhe = t;
}
void Show()
{
cout << "书名：" << std::left << setw(20) << name << std::right << setw(6) << "\t日期：" << riqi << "\t数量：" << num << "\t作者:"<<zuozhe<<"\t出版社:" << chubanshe << "\t类别:" << leibie << "\t编号：" << bianhao << "\tISBN:" << ISBN << endl;
}
void Set()
{
cout << "请输入书名:";
cin >> name;
cout << "请输入日期:";
cin >> riqi;
cout << "请输入数量:";
cin >> num;
cout << "请输入作者:";
cin >> zuozhe;
cout << "请输入出版社:";
cin >> chubanshe;
cout << "请输入类别:";
cin >> leibie;
cout << "请输入编号:";
cin >> bianhao;
cout << "请输入ISBN:";
cin >> ISBN;
}
void Addnum()
{
int n;
cout << "请输入归还的数量：";
cin >> n;
num += n;
}
void Borrownum()
{
int n;
cout << "请输入借出的数量：";
cin >> n;
num -= n;
}
public:
string name;
int riqi;//出版日期
int num;//剩余数量
string chubanshe;//出版社
string leibie;//类别
int bianhao;//编号
int ISBN;//ISBN
string zuozhe;//作者
};
void menu()
{
cout << "--------------------------------------欢迎进入图书管理系统--------------------------------------" << endl;
cout << endl << "0 - 退出系统；" << "1 - 显示库存；" << "2 - 查询图书；" << "3 - 借阅图书；" << "4 - 归还图书；" << "5 - 增加图书；" << "6 - 删除图书；" <<"7 -排序图书；"<< endl;
}
class Booklist//创建BookList类，数据成员有Book还有图书数量
{
public:
void save()//新建图书的话保存数据，用app方式打开文件
{
ofstream fout(filename, ios::app);
list<Book>::iterator it = BList.begin();
for (int i = 0; i < num - 1; i++)//偏移迭代器，指向新加入的Book并写入文件
{
it++;
}
for (; it != BList.end(); it++)
{
fout << (*it).name << ' ' << (*it).riqi << ' ' << (*it).num << (*it).chubanshe<<' '<<(*it).zuozhe<<' '<<(*it).leibie << ' ' << (*it).ISBN << ' ' << (*it).bianhao << ' ' << '\n';
}
fout.close();
}
void resave()
{
ofstream fout(filename, ios::out);//重新写入数据，因为删除了某个元素
if (fout.is_open())
{
for (list<Book>::iterator it = BList.begin(); it != BList.end(); it++)
{
fout << (*it).name << ' ' << (*it).riqi << ' ' << (*it).num << (*it).chubanshe << ' ' << (*it).zuozhe << ' ' << (*it).leibie << ' ' << (*it).ISBN << ' ' << (*it).bianhao << ' ' << '\n';
}
}
fout.close();
}
void Show()
{
for (list<Book>::iterator it = BList.begin(); it != BList.end(); it++)
{
(*it).Show();
}
}
void adddata()//添加数据
{
Book B;
B.Set();
BList.push_back(B);
num++;
}
void start()//程序一开始读取文件里的数据
{
string na;
int n;
int p;
string m;
string o;
int s;
int r;
string t;
ifstream fin(filename, ios::in);
if (fin.is_open())
{
while (fin >> na >> p >> n>> m>> o>> s>> r>> t)
{
Book B(na, p, n,m,o,s,r,t);
BList.push_back(B);
num++;
}
}
fin.close();
}
void increase()
{
cout << "请输入书名：" << endl;
string n;
cin >> n;
for (list<Book>::iterator it = BList.begin(); it != BList.end(); it++)
{
if ((*it).name == n)
(*it).Addnum();
}
resave();
}
void decrease()
{
cout << "请输入书名：" << endl;
string n;
cin >> n;
for (list<Book>::iterator it = BList.begin(); it != BList.end(); it++)
{
if ((*it).name == n)
(*it).Borrownum();
}
resave();
}
void FindBook()
{
string name;
cin >> name;
for (list<Book>::iterator it = BList.begin(); it != BList.end(); it++)//遍历整个list，所以符合关键字的都会被找到
{
int index = (*it).name.find(name);//如果没找到返回值是一个很大的数
if (index < (*it).name.length())
(*it).Show();
}
}
bool paixuguize(Book &b1, Book &b2)//排序规则
{
if (b1.leibie == b2.leibie)
{
if (b1.num == b2.num)
{
return b1.ISBN < b2.ISBN;
}
else
{
return b1.num < b2.num;
}
}
else {
return b1.leibie < b2.leibie;
}
}
//void show(list<Book>&b1) //排序后的显示
//{
// for (list<Book>::iterator it = BList.begin(); it != BList.end(); it++)
// {
// cout<<"姓名:"<< (*it).name << ' ' <<"日期:" << (*it).riqi << ' ' <<"数量：" << (*it).num <<"出版社："<< (*it).chubanshe << ' ' <<"作者:"<< (*it).zuozhe << ' ' <<"类别:"<< (*it).leibie << ' ' << "ISBN:"<<(*it).ISBN << ' ' << "编号:"<<(*it).bianhao << ' ' << '\n';
// }
//}
void paixu()//进行排序并打印
{
BList.sort(paixuguize);
resave();
}
void DeleteBook()
{
string name;
cout << "请输入书名：";
cin >> name;
int i = 0;
for (list<Book>::iterator it = BList.begin(); it != BList.end(); it++)
{
if ((*it).name == name)
break;
++i;
}
list<Book>::iterator it = BList.begin();
advance(it, i);
BList.erase(it);
--num;
resave();
}
public:
list<Book>BList;
int num = 0;
};
int main()
{
Booklist B1;
B1.start();
while (1)
{
menu();
int key;
cout << "请输入要进行的操作：";
cin >> key;
switch (key)
{
case 0:
return 0;
break;
case 1:
B1.Show();
break;
case 2:
B1.FindBook();
break;
case 3:
B1.decrease();
break;
case 4:
B1.increase();
break;
case 5:
{
B1.adddata();
B1.save();
break;
}
case 6:
B1.DeleteBook();
break;
case 7:
B1.paixu();
break;
}
}
}
