// CS240 Fall 2009
// Lab 02 Solution
// JC Chin
#include <stdio.h>

// Get an integer from STDIN. Inputs are separated by \n and EOF.
// Return: The integer read from STDIN.
int getInteger()
{
	char temp;
	int total = 0;

	while(((temp = getchar()) != '\n') && (temp != EOF)) {
		if (temp < '0' || temp > '9')
			return -1;

		total = total * 10 + temp - '0';
	}

	return total;
}

int main()
{
	int i;
	int temp;
	double rate;
	double deposit;
	double amount[12];

	// Inputs from the user
	printf("Amount of money to deposit every month: ");
	deposit = getInteger();

	if(deposit < 0)	// make sure the deposit amount is positive.
		return 0;

	printf("Annual interest rate (%%): ");
	rate = getInteger();

	if(rate < 0)		// make sure the interest rate is positive.
		return 0;

	// Compute the monthly interest rate.
	// rate / 100.0 because the input is percentage.
	rate = rate / (100.0 * 12.0) + 1.0;

	// Compute the balance
	amount[0] = deposit * rate;
	for(i = 1; i < 12; i++)
		amount[i] = (amount[i-1] + deposit) * rate;

	// Print out the balance
	printf("\n");
	printf("Month      Balance\n");
	printf("==================\n");
	for (i = 11; i >= 0; i--)
		printf("%2d %15.2lf\n", i+1, amount[i]);
}