Question

Implement this C program using at least three arrays to store the interest, principle and balance after each payment respectively. For example, interest[0] stores the paid interest in the first payment. Besides, please use three pointers to visit the element in the three arrays separately. Name this C program as loanCalcPtr.c.

Answer 1

#include <stdio.h>

#include <math.h>

#include <stdlib.h>

int main()

{

float principalAmount, annualInterstRate, monthlyInterestRate;

float equatedMonthlyInstallment , initialBalance, interest, principalPaid, finalBalance;

int totalMonths, month;

float interestList[30], principalPaidList[30], finalBalanceList[30];

printf(" principalAmount: ");

scanf("%f", &principalAmount);

printf(" Annual Interest rate: ");

scanf("%f", &annualInterstRate);

printf(" Term in month: ");

scanf("%d", &totalMonths);

monthlyInterestRate = (float)(annualInterstRate / (12*100.0));

equatedMonthlyInstallment = principalAmount * (monthlyInterestRate / (1 - pow( (1 + monthlyInterestRate) , (-totalMonths) )));

initialBalance = principalAmount;

printf(" Monthly Payment: $%.2f ", equatedMonthlyInstallment );

for(month = 1; month <= totalMonths; month++)

{

*(interestList+month-1) = (initialBalance * monthlyInterestRate);

*(principalPaidList+month-1) = equatedMonthlyInstallment - *(interestList+month-1);

*(finalBalanceList+month-1) = (initialBalance - *(principalPaidList+month-1));

initialBalance = *(finalBalanceList+month-1);

}

printf(" %10s %14s %10s %10s ", " Payment ", " principalAmount ", " Interest ", " Balance ");

for(month = 1; month <= totalMonths; month++)

{

printf(" %6d $%-10.2f $%-10.2f $%-12.2f ", month, *(principalPaidList+month-1), *(interestList+month-1), *(finalBalanceList+month-1));

}

printf(" Final Payment: $%.2f ", equatedMonthlyInstallment );

printf(" ");

return 0;

}

Step-by-step explanation:

• Get the information about principal amount, interest rate, total months as an input from user.
• Calculate equated monthly installment and display monthly payment.
• Use relevant formulas to calculate loan schedule , interest, principal amount and final balance accordingly.
• Update initial balance with final balance and display headers , final payment and final payment .