/*  Craig Persiko - FunInterest.java
    Sample Program using loops and a function for CS 111A

    Uses a function to compute the new balance of a
    specified investment with 5% interest after a period
    of 10 years.  Then uses the same function to show the
    new balance of the same initial investment at other
    interest rates and time periods.
*/

import java.util.Scanner;


class FunInterest
{
  public static void main(String args[])
  {
    Scanner keyIn = new Scanner(System.in);
    double init_balance, new_balance;

    System.out.print("Welcome to Investment World\nEnter amount to be invested: ");
    init_balance = keyIn.nextDouble();

    // Compile interest for 10 years at 5%

    new_balance = accrue_interest(init_balance, 0.05, 10);
    // Output the result

    System.out.printf("After 10 years at 5%%, your balance will be: $%,.2f\n", new_balance);

    // Compile interest for 10 years at 10%

    new_balance = accrue_interest(init_balance, 0.10, 10);
    // Output the result

    System.out.printf("After 10 years at 10%%, your balance will be: $%,.2f\n",
                      new_balance);

    // Output the result of compiling interest

    // for 7 years at 10%

    System.out.printf("After 7 years at 10%%, your balance will be: $%,.2f\n",
                      accrue_interest(init_balance, 0.10, 7));

  }


  /*  *****  accrue_interest method  *****
     Returns the new balance when cur_balance is invested for
     specified number of years at specified interest rate.
  */
  static double accrue_interest(double cur_balance, double rate, int years)
  {
    int elapsed_years = 0;

    while(elapsed_years < years) // For specified number of years...

    {
      cur_balance += cur_balance * rate;  // Add interest to the balance

      elapsed_years++;  // Add 1 to elapsed_years

    }

    return cur_balance;
  }
}

/*  SAMPLE OUTPUT:

Welcome to Investment World
Enter amount to be invested: 100
After 10 years at 5%, your balance will be: $162.89
After 10 years at 10%, your balance will be: $259.37
After 7 years at 10%, your balance will be: $194.87

*/