c++ memory leak problem...HELP..~~~

[ToT]

when I run it always appear, it stops work....
I don't know why, my classmate said it is about the memory leak problem, but he
also don't know how to fix it.

#include<iostream>
#include<fstream>
#include<string>
using namespace std;


class expensive
{

private:
    int len;
    string *Name = new string[len];
    double *Money = new double [len];
    string *Breakfast = new string[4];
    string *Lunch = new string[5];
    string *Dinner = new string[4];
    double b=0,l=0,d=0;
public:
    void getcategory()
    {
        fstream infile("Categ.txt");
        for(int i=0;i<4;i++)
        {
            infile>>Breakfast[i];
        }
        for(int i=0;i<5;i++)
        {
            infile>>Lunch[i];
        }
        for(int i=0;i<4;i++)
        {
            infile>>Dinner[i];
        }
    }

    void getexpensive1()
    {
        fstream infile("expense.txt");
        len=12;
        for(int i=0;i<len;i++)
        {
            infile >> Name[i]>>Money[i];
        }
    }

    void getexpensive2()
    {
        fstream infile("expense2.txt");
        len=13;
        for(int i=0;i<len;i++)
        {
            infile >> Name[i]>>Money[i];
        }
    }

    void getexpensive3()
    {
        fstream infile("expense3.txt");
        len=8;
        for(int i=0;i<len;i++)
        {
            infile >> Name[i]>>Money[i];
        }
    }


    void totalexpensive()
    {
        for(int i=0;i<4;i++)
            for(int j=0;j<20;j++)
        {
            if(Breakfast[i]==Name[j])
                b+=Money[j];
        }
        for(int i=0;i<5;i++)
            for(int j=0;j<20;j++)
        {
            if(Lunch[i]==Name[j])
                l+=Money[j];
        }
        for(int i=0;i<4;i++)
            for(int j=0;j<20;j++)
        {
            if(Dinner[i]==Name[j])
                d+=Money[j];
        }
    }
    void display()
    {
        cout<<"Total expensive report: "<<endl;
        cout<<Breakfast[0]<<"   "<<b<<endl;
        cout<<Lunch[0]<<"  "<<l<<endl;
        cout<<Dinner[0]<<"  "<<d<<endl;
        cout<<endl;
    }

    void update()
    {
        ofstream outfile("report.txt");
        outfile<<"Total expensive report: "<<endl;
        outfile<<Breakfast[0]<<"   "<<b<<endl;
        outfile<<Lunch[0]<<"  "<<l<<endl;
        outfile<<Dinner[0]<<"  "<<d<<endl;
        outfile<<endl;
    }
};

int main()
{
    int command=-1;
    cout <<"Input integers for this program.\nChoose which expense category you want to calculate.\nCommand list:\n1.expense1.\n2.expense2.\n3.expense3.\n0.exit.\n";

    while(command){
        cin>>command;
        switch (command){
            case 0:
                cout << "exit.";
                break;
            case 1:
                {
                    expensive e1;
                    e1.getexpensive1();
                    e1.getcategory();
                    e1.totalexpensive();
                    e1.display();
                    e1.update();
                    break;
                }
            case 2:
                {
                    expensive e2;
                    e2.getexpensive2();
                    e2.getcategory();
                    e2.totalexpensive();
                    e2.display();
                    e2.update();
                    break;
                }
            case 3:
                {
                    expensive e3;
                    e3.getexpensive3();
                    e3.getcategory();
                    e3.totalexpensive();
                    e3.display();
                    e3.update();
                    break;
                }
        }
    }

    return 0;
}

[helios]

1. expensive has no user-defined destructor, so all pointers it has allocated (lines 12-16) are leaked every time an instance goes out of scope/is deleted.
2. expensive::Name and expensive::Money are initialized to arrays of unknown length, because expensive::len is not initialized at construction.
3. Lines 39, 49, and 59: Just setting expensive::len does not affect the length of the arrays pointed to by expensive::Name or expensive::Money.
4. expensive::totalexpensive() attempts to read the arrays pointed to by expensive::Name and expensive::Money up to offset 19, even though no function appears to write to these arrays past offset 12.

Overall the class is ill-defined, in my opinion. For example, expensive::getexpensive1(), expensive::getexpensive2(), and expensive::getexpensive3() should be a single function at most. It doesn't seem like the class should concern itself with I/O. I would suggest redoing it from scratch.