Please,give one or two programmes using do...while loop in c++?

Here is a program on interest calculation
using do while
loop

#include<iostream.h>

#include<conio.h>

float
cal (float amt, int year, float rate=15);

void prn (char
c='*');

void main
()

{

clrscr();

float
amount, interest;

int
year;

cout<<"Enter the amount on which
interest has to be calculated:
-";

cin>>amount;

cout<<"Enter
the number of years:
-";

cin>>year;

interest=cal
(amount, year);

prn
();

cout<<"The interest
on-"<<amount<<"-for the period
of-"<<year<<" years would
be"<<interest<<endl;

prn
('-');

getch
();

}

float cal (float amt,
int year, float rate)

{

int
i;

float
sum=amt;

i=1;

do

{

sum=sum
* (1+
(rate/100));

i++;

}while(i<=year);

return
sum-amt;

}

void prn (char
c)

{

for (int i=0;
i<40;
i++)

{

cout<<c;

}

cout<<endl;

}