C++ : Coverting Loop Based Logic - c++

Question

I was assigned a task to create a Program with the following conditions:
Write a C++ program which accepts amount in rupees as input (integer) within
Range from Rs. 100 to Rs. 100000 and then asks the user for particular currency note
preference and display the total number of Currency Notes of Rs. 500, 100, 50, 20, 10, 5 and 1.
The user can be given a maximum of 200 notes of his preferred choice.
For example: when a user enters a number, Rs. 57477 and enters 50 notes as his preferred
choice, the results would be like this.
Currency Note : Number
500 : 74
100 : 4
50 : 200
20 : 3
10 : 1
5 : 1
1 : 2
I created the above program using Modulo Operator and While Loop.
Part of my code is as Follows:
if (preference == 500)
{
notes500 = rupees/500; //This get all the 500 notes
rupees %= 500; //this will find the remaining rupees after deducting all the 500 notes
while(notes500 > 200) //this loop will make sure the obtained 500 notes are not greater that 200
{
notes500 -=1;
rupees +=500; //this re add all the 500 notes that are not needed back to main amount
}
notes100 = rupees/100; //from here we will get all the 100 notes
rupees %= 100; //from here we will substract the amount of Rs 100 notes obtained
//this process will continue to till it reaches 1 rupee notes
notes50 = rupees/50;
rupees %= 50;
notes20 = rupees/20;
rupees %= 20;
notes10 = rupees/10;
rupees %= 10;
notes5 = rupees/5;
rupees %= 5;
notes1 = rupees;
}
This same logic will continue for other preferences.
Now the following restrictions have been applied on the program:
Use of Loops or Recursions is not allowed.
Arrays are also not allowed.
Program should be made using basic knowledge of C++ (e.g. by using decision control structures, C++ operators, e.t.c.)
Now how am i supposed to create the above program without loops?
Help will be highly appreciated!
Thanks,

Answer 1

This code answers the question "how am i supposed to create the above program without loops?" It is achieved by Meta Programming with templates. The recursion constraint is solved as well because the compiler builds out the iterative code. However, I could not solve the preferred note constraint. I process the preferred denomination first but there are many cases like preferred note 1 and rupees total of 201. Looking forward to see the ultimate solution.
#include <iostream>
template <int denom, typename T>
class VegasCashier {
public:
static T result(T a, T b) {
int leftOver = b;
int dcount = 0;
if (denom == 0) // First time in process the favorite
{
leftOver = b;
dcount = b / a;
leftOver %= a;
// From Pete's Comment
if (dcount > 200) { leftOver += a * (dcount - 200); dcount = 200; }
if (dcount > 0)
std::cout << "\tGive " << dcount << " of Denomination "
<< a << " (Favorite) " << std::endl;
}
else if (b != 0 && a != denom) // c is the favorite
{
leftOver = b;
dcount = b / denom;
leftOver %= denom;
// From Pete's Comment
if (dcount > 200) { leftOver += denom * (dcount - 200); dcount = 200; }
if (dcount > 0)
std::cout << "\tGive " << dcount << " of Denomination "
<< denom << std::endl;
}
if (denom == 0) // Special case for desired denomination
return VegasCashier <500, T>::result(a, leftOver); // Start cashout at highest denom
else if (denom == 500)
return VegasCashier<100, T>::result(a, leftOver);
else if (denom == 100)
return VegasCashier<50, T>::result(a, leftOver);
else if (denom == 50)
return VegasCashier<20, T>::result(a, leftOver);
else if (denom == 20)
return VegasCashier<10, T>::result(a, leftOver);
else if (denom == 10)
return VegasCashier<5, T>::result(a, leftOver);
else if (denom == 5)
return VegasCashier<1, T>::result(a, leftOver);
return dcount;
}
};
// This template stops the implementation
template < typename T>
class VegasCashier<1, T> {
public:
static T result(T a, T b) {
if ( b > 0 )
std::cout << "\tGive " << b << " of Denomination " << 1 << std::endl;
return 0;
}
};
// Starting function
template <int denom, typename T>
inline T CasinoResults(T a, T b)
{
std::cout << "\nCashing out " << b << "..." << std::endl;
return VegasCashier<0, T>::result(a, b);
}
int main()
{
CasinoResults<0>(5, 5006);
CasinoResults<0>(500, 99502);
CasinoResults<0>(500, 7519);
CasinoResults<0>(1, 7509); // Fails the Preferred note constraint
}