code:

#include 
#include 
#include 
#include 
#include 
#include 

	// Cyrax Creations
	// cyrax_000@hotmail.com
	// 
	// Ohm's law

int i, v, r, choice;

void input()
{
	system("cls");
	do
	{
		cout<<"\n\n";
		cout<<"\t1. Calculate current\n";
		cout<<"\t2. Calculate Voltage\n";
		cout<<"\t3. Calculate Restistance\n\n";
		cout<<"\t0. Quit\n\n\n";
		cout<<"\t Enter your choice => ";
		cin>>choice;
	}
	while ((choice < 0) && (choice > 3));
}

void calc()
{
	if (choice == 1) 
	{
		system("cls");
		cout<<"\n\n\n";
		cout<<"\tEnter Voltage => ";
		cin>>v;
		cout<<"\tEnter Resistance => ";
		cin>>r;
		// ENTER OHM'S FORMULA HERE
		// i = formula_here, remove double slash;
		cout<<"\n\n";
		cout<<" Current = "<< i <<".";
		cout<<"\n\n\n\n";
	}
		if (choice == 2) 
	{
		system("cls");
		cout<<"\n\n\n";
		cout<<"\tEnter Current => ";
		cin>>i;
		cout<<"\tEnter Resistance => ";
		cin>>r;
		// ENTER OHM'S FORMULA HERE
		// v = formula_here, remove double slash;
		cout<<"\n\n";
		cout<<" Voltage = "<< v <<".";
		cout<<"\n\n\n\n";
	}
		if (choice == 3) 
	{
		system("cls");
		cout<<"\n\n\n";
		cout<<"\tEnter Current => ";
		cin>>i;
		cout<<"\tEnter Voltage => ";
		cin>>v;
		// ENTER OHM'S FORMULA HERE
		// r = formula_here, remove double slash;
		cout<<"\n\n";
		cout<<" Resistance = "<< r <<".";
		cout<<"\n\n\n\n";
	}

}

void main()
{
	input();
	calc();
}