Invoicing management system, just learn C + +

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#include <iostream>

#include <string>
using namespace Std;
int g=0;//Define global variables//Total number of existing goods
int S=0;//staff Number of employees
Double t=0;//Total turnover
Create the first Class (cargo)
Class goods
{
Public
String id;//
String name;//Name
Double price;//Price
int num;//Number
}goods[10000];//Defining arrays
Class staff//second category (staff)
{
Public
String ID;
String name;
Double sale;//turnover
}STAFF[1000];
Class Manager
{
Public
virtual void Show ()//virtual function
{
cout<< "Show method for managing base classes" <<endl;
}
};
Class Salemanager:public manager//derived from one of the classes
{
Public
String Salemenu;
Salemanager ()
{
Salemenu= "---sales management---\n1. Sales \n2. Sales refund \n3. New Salesperson Information 4. Sales statistics \n0. Return to main Menu \ n Please enter your choice:";
}
void Show ()
{
int n,i,j;
Do
{
cout<<salemenu;
cin>>n;
if (n==1)
{
int num,d=1;
String A, B;
cout<< "Please enter the sales employee number:";
cin>>b;
for (i=1;i<=s;i++)
if (b==staff[i].id)
{
D=0;
Break
}
if (d)
{
cout<< "Employees who do not have this number. "<<endl;
System ("pause");
Break
}
d=1;
cout<< "Please enter the number of the sales product:" <<endl;
cin>>a;
for (j=1;j<=g;j++)
if (a==goods[j].id)
{
D=0;
Break
}
if (d)
{
cout<< "There are no items for this number. "<<endl;
System ("pause");
Break
}
cout<< "Please enter sales:" <<endl;
cin>>num;
if (num>goods[i].num)
cout<< "not so much stock. "<<endl;
Else
{
Calculation of staff[i].sale+=num*goods[j].price;//turnover
Goods[j].num-=num;
T+=num*goods[j].price;
}
}
else if (n==2)
{
int num,d=1;
String A, B;
cout<< "Please enter the employee number of the refund:";
cin>>b;
for (i=1;i<=s;i++)
if (b==staff[i].id)
{
D=0;
Break
}
if (d)
{
cout<< "Employees who do not have this number. "<<endl;
System ("pause");
Break
}
d=1;
cout<< "Please enter the number of the refund item:" <<endl;
cin>>a;
for (j=1;j<=g;j++)
if (a==goods[j].id)
{
D=0;
Break
}
if (d)
{
cout<< "There are no items for this number. "<<endl;
System ("pause");
Break
}
cout<< "Please enter the amount of refund:" <<endl;
cin>>num;
Staff[i].sale-=num*goods[j].price;
Goods[j].num+=num;
T-=num*goods[j].price;
}
else if (n==3)
{
s++;
cout<< "Please enter the new employee number:";
cin>>staff[s].id;
cout<< "Please enter the name of the new employee:";
cin>>staff[s].name;
cout<< "Please enter new employee turnover:";
cin>>staff[s].sale;
}
else if (n==4)
{
int i;
cout<< "number \ t name \ t Sales" <<endl;
for (i=1;i<=s;i++)
cout<<staff[i].id<< "\ t" <<staff[i].name<< "\ T" <<staff[i].sale<<endl;
}
}
while (n);
}
};
Class Savemanager:public Manager
{
Public
String Savemenu;
Savemanager ()
{
Savemenu= "---inventory management---\n1. Check inventory \n0. Return to the main menu \ n Please enter your choice:";
}
void Show ()
{
int n,i;
Do
{
cout<<savemenu;
cin>>n;
if (n==1)
{
cout<< "No. \ t name \ t unit price \ t Stock" <<endl;
for (i=1;i<=g;i++)
cout<<goods[i].id<< "\ t" <<goods[i].name<< "\ T" <<goods[i].price<< "\ T" << goods[i].num<<endl;
}
}
while (n);
}
};
Class Buymanager:public Manager
{
Public
String Buymenu;
Buymanager ()
{
Buymenu= "---procurement management---\n1. Buy the original item \n2. Buy a new item \n0. Return to the main menu \ n Please enter your choice:";
}
void Show ()
{
int n,i;
Do
{
cout<<buymenu;
cin>>n;
if (n==1)
{
int num,d=1;
Double p;
String A;
cout<< "Please enter the number of goods to buy:";
cin>>a;
for (i=1;i<=g;i++)
if (a==goods[i].id)
{
D=0;
Break
}
if (d)
{
cout<< "There are no goods of that number. "<<endl;
System ("pause");
Break
}
cout<< "Please enter the purchase price:";
cin>>p;
cout<< "Please enter buy quantity:";
cin>>num;
Goods[i].num+=num;
T-=num*p;
}
else if (n==2)
{
g++;
cout<< "Please enter the new cargo number:";
cin>>goods[g].id;
cout<< "Please enter the new cargo name:";
cin>>goods[g].name;
cout<< "Please enter the price of new goods:";
cin>>goods[g].price;
cout<< "Please enter the quantity of new goods:";
cin>>goods[g].num;
T-=goods[g].num*goods[g].price;
}
}
while (n);
}
};
Class Moneymanager:public Manager
{
Public
String Moneymenu;
Moneymanager ()
{
Moneymenu= "---financial management---\n1. Query turnover \n0. Return to main Menu \ n Please enter your choice:";
}
void Show ()
{
int n;
Do
{
cout<<moneymenu;
cin>>n;
if (n==1) cout<< "turnover:" <<T<<endl;
}
while (n);
}
};
Class Form
{
Public
int n;
String Strword;
form (String str)
{
STRWORD=STR;
}
void input ()
{
Do
{
System ("CLS");
cout<<strword;
cin>>n;

if (n==1)
{
Salemanager m;
Addfun (&AMP;M);
}
else if (n==2)
{
Savemanager m;
Addfun (&AMP;M);
}
else if (n==3)
{
Buymanager m;
Addfun (&AMP;M);
}
else if (n==4)
{
Moneymanager m;
Addfun (&AMP;M);
}
}while (n);
}
Add a Feature object to a menu class object
void Addfun (Manager *m)
{
M->show ();
}
};
void Main ()
{
String Menu,salemenu,savemenu,buymenu,moneymenu;
menu= "= = Invoicing ===\n";
menu+= "1. Sales management \ n";
menu+= "2. Inventory management \ n";
menu+= "3. Procurement management \ n";
menu+= "4. Financial management \n0. exit \ n Please enter your choice:";
Form f (menu);
F.input ();
}

Invoicing management system, just learn C + +