HHW CTOR AND DTOR (2)

#include<iostream.h>
#include<conio.h>
#include<stdlib.h>
class deposit
{
long int principal;
int time;
float rate;
float total_amt;
int r;
public:
deposit();
deposit(long p,int t,float f);
deposit(long p,int t);
deposit(long p,float r);
void calc_amt(void);
void display(void);
};
deposit :: deposit()
{
principal=time=rate=0.0;
}
deposit :: deposit(long p,int t,float r)
{
principal=p;time=t;rate=r;
}
deposit :: deposit(long p,int t)
{
principal=p;time=2;rate=r;
}
deposit :: deposit(long p,float r)
{
principal=p;time=2;rate=r;
}
void deposit :: calc_amt(void)
{
total_amt=principal+(principal*time*rate)/100;
}
void deposit :: display(void)
{
cout<<"\nprincipal amount : rs. "<<principal;
cout<<"\t\tperiod of investment : "<<time<<"years";;
cout<<"\nrate of intrest : "<<rate;
cout<<"\t\ttotal amount : rs. "<<total_amt<<"\n";
}
int main()
{
clrscr();
deposit d1,d2(200,2,0.07f),d3(4000,1),d4(3000,0.12f);
d1.calc_amt();
d2.calc_amt();
d3.calc_amt();
d4.calc_amt();
cout<<"object 1\n :";d1.display();
cout<<"object 2\n :";d2.display();
cout<<"object 3\n :";d3.display();
return 0;
}