Add arrays to my code, need help

[ashmad10]

#include "stdafx.h"
#include <iostream>
#include <cstdlib>

using namespace std;
int nMonths = 0;
float loanAmount;
int totalPaid = 0.0f;

void process() {

float interestRate;
float monthlyPayment;
cout << "What is the amount of the loan?:$";
cin >> loanAmount; cin.ignore();
cout << "What is the interest rate on the loan?:$";
cin >> interestRate; interestRate /= 100; cin.ignore();
cout << "What is the desired monthly payment?:$";1
cin >> monthlyPayment; cin.ignore();
while (monthlyPayment < loanAmount * interestRate / 12) {
cout << "Not a valid amount, Amount must be greater than $";
cout << (loanAmount * interestRate / 12) << endl;
cout << "What is the desired monthly payment amount? $";
cin >> monthlyPayment; cin.ignore();
}
float interestToAdd = 0.0f;
float remaining = loanAmount;
float toAdd = 0.0f;
cout << endl;
cout << "Month" << " (Interest Added)" << " (Amount Paid)" << " (Debt Remaining)" << endl;
while (remaining > monthlyPayment) {
interestToAdd = remaining * interestRate / 12;
nMonths++;
remaining += interestToAdd;
if (remaining > monthlyPayment) {
toAdd = monthlyPayment;
}
else {
toAdd = remaining;
}
cout << nMonths << " $" << interestToAdd << " $" << toAdd
<< " $" << remaining << endl;
totalPaid += toAdd;
remaining -= toAdd;
}

}
void displayResult() {

cout << endl << "Statistics about loan. " << endl;
cout << "Initial loan amount: $" << loanAmount << endl;
cout << "Total amount paid: $" << totalPaid << endl;
cout << "Time to pay off loan: " << nMonths << endl;
cout << "Overpay percentage: " << (totalPaid / loanAmount) << endl;
cin.ignore();

}
void chooseletterA() {

float Amount, rateOfIntrest, monthlyAmountToPay, totalAmount;

int lengthOfLoan;

cout << "What is the amount of the loan?:$";

cin >> Amount;

cin.ignore();

cout << "What is the interest rate on the loan?";

cin >> rateOfIntrest;

rateOfIntrest /= 100;

cin.ignore();

cout << "What is the length of loan?:$";

cin >> lengthOfLoan;

monthlyAmountToPay = (Amount*rateOfIntrest*pow((1 + rateOfIntrest), lengthOfLoan)) / (pow((1 + rateOfIntrest), lengthOfLoan - 1));

cout << "Your monthly loan payment amount = $" << monthlyAmountToPay << endl;

system("pause");

}

void chooseletterB() {

float Amount, rateOfIntrest, monthlyAmountToPay, totalAmount;

int lengthOfLoan;

cout << "What is the monthly amount of the loan?:$";

cin >> monthlyAmountToPay;

cin.ignore();

cout << "What is the interest rate on the loan?";

cin >> rateOfIntrest;

rateOfIntrest /= 100;

cin.ignore();

cout << "What is the length of loan?:$";

cin >> lengthOfLoan;

cin.ignore();

Amount = monthlyAmountToPay * pow((1 + rateOfIntrest), lengthOfLoan - 1) / (rateOfIntrest*pow((1 + rateOfIntrest), lengthOfLoan));

cout << "Your total loan amount = $" << Amount << endl;

system("pause");

}

void chooseletterC() {

float Amount, rateOfIntrest, monthlyAmountToPay, totalAmount;

int lengthOfLoan;

cout << "What is the amount of the loan?:$";

cin >> Amount;

cin.ignore();

cout << "What is the monthly amount of the loan?:$";

cin >> monthlyAmountToPay;

cin.ignore();

cout << "What is the length of loan?:$";

cin >> lengthOfLoan;

cin.ignore();

rateOfIntrest = ((monthlyAmountToPay *lengthOfLoan) - Amount) / lengthOfLoan;

cout << "Your monthly monthly rate of intrest = $" << rateOfIntrest / 12 << endl;

system("pause");

}

void chooseletterD() {

float Amount, rateOfIntrest, monthlyAmountToPay, totalAmount;

int lengthOfLoan;

cout << "What is the amount of the loan?:$";

cin >> Amount;

cin.ignore();

cout << "What is the monthly amount of the loan?:$";

cin >> monthlyAmountToPay;

cin.ignore();

cout << "What is the interest rate on the loan?";

cin >> rateOfIntrest;

rateOfIntrest /= 100;

cin.ignore();

lengthOfLoan = (log(Amount) - log(monthlyAmountToPay)) / (log(1 + rateOfIntrest));

cout << "Your length of loan amount = $" << lengthOfLoan << endl;

system("pause");

}

void multipleChoice() {

cout << "Welcome to the multiple choice part of the program, please choose a letter: " << endl;

cout << "A: Monthly payment " << endl;

cout << "B: Loan amount " << endl;

cout << "C: Length of loan " << endl;

cout << "D: Interest rate " << endl;

char ch;

cin >> ch;

switch (ch)

{

case 'A':

chooseletterA();

cout << "First question: Please solve for monthly payment. " << endl;

break;

case 'B':

chooseletterB();

cout << "Second question: Please solve for loan amount. " << endl;

break;

case 'C':

chooseletterC();

cout << "Third question: Please solve for length of loan. " << endl;

break;

case 'D':

chooseletterD();

cout << "Forth question: Please solve for interest rate. " << endl;

break;
}

}
int main()

{
int ch;
do {
cout << endl << "************************MENU***************************" << endl;
cout << "1. Process Loan" << endl;
cout << "2. Display Result" << endl;
cout << "3. MultipleChoice" << endl;
cout << "Enter your choice: ";
cin >> ch;
switch (ch) {
case 1:
process();
break;
case 2:
displayResult();
break;
case 3:
multipleChoice();
break;
default:
cout << "\nEntered Wrong Keyword....\nRe-enter Again";
break;
}
} while (ch < 3 && ch > 0);
return 0;



}