(Fraction calculator) Write a program that lets the user perform arithmetic operations on fractions. Fractions are of the form a/b, in which a and b are integers and b 6¼ 0. Your program must be menu driven, allowing the user to select the operation (+, -, *, or /) and input the numerator and denominator of each fraction.

#include "stdafx.h"

#include <iostream>

using namespace std;

void choice(int &a,int &b,int &c,int &d,char ch,int &upper,int &lower);

int sum(int a,int b,int c,int d,int &upper,int &lower);

int mul(int a,int b,int c,int d,int &upper,int &lower);

int div(int a,int b,int c,int d,int &upper,int &lower);

int sub(int a,int b,int c,int d,int &upper,int &lower);

int a,b,c,d,nom,den;

char operation;

int main()

{

            choice(a,b,c,d,operation,nom,den);

            cout<<"answer is "<<nom<<"/"<<den<<endl;

            system("pause");

            return 0;

}

void choice(int &a,int &b,int &c,int &d,char ch,int &nom,int &den)

{

            cout<<"enter a,b,c,d"<<endl;

            cin>>a>>b>>c>>d;

            cout<<"enter opperation "<<endl;

            cin>>ch;

            switch(ch)

            {

            case '+':

                        sum(a,b,c,d,nom,den);

                        break;

            case '*':

                        mul(a,b,c,d,nom,den);

                        break;

            case '/':

                        div(a,b,c,d,nom,den);

                        break;

            case '-':

                        sub(a,b,c,d,nom,den);

                        break;

            }

}

int sum(int a,int b,int c,int d,int &nom,int &den)

{

            nom=a*d+b*c;

            den=b*d;

            return nom;

            return den;

}

int mul(int a,int b,int c,int d,int &nom,int &den)

{

            nom=a*c;

            den=b*d;

            return nom;

            return den;

}

int sub(int a,int b,int c,int d,int &nom,int &den)

{

            nom=a*d-b*c;

            den=b*d;

                        return nom;

            return den;

}

int div(int a,int b,int c,int d,int &nom,int &den)

{

            nom=a*d;

            den=b*c;

                        return nom;

            return den;

}