/*  Interest.c  (c) Kari Laitinen

    http://www.naturalprogramming.com/

    2013-11-22 File created.
    2013-11-22 Last modification.
*/

#include  <stdio.h>

int main()
{
   float  compound_interest_table [ 3 ] [ 8 ]  =
   {
     { 5.00, 10.25, 15.76, 21.55, 27.63, 34.01, 40.71, 47.75 },
     { 6.00, 12.36, 19.10, 26.25, 33.82, 41.85, 50.36, 59.38 },
     { 7.00, 14.49, 22.50, 31.08, 40.26, 50.07, 60.58, 71.82 }
   } ;

   float  given_sum_of_money ;
   int    interest_percentage,  loan_period_in_years ;

   printf( "\n This program calculates the compound interest"
           "\n for a given sum of money (principal). \n"
          "\n  Give the loan amount: " ) ;
   scanf( "%f", &given_sum_of_money ) ;

   printf( "\n  Give the interest percentage ( 5, 6, or 7): ) " ) ;
   scanf( "%d", &interest_percentage ) ;

   printf( "\n  Give the loan period in years ( max. 8 ): " ) ;
   scanf( "%d", &loan_period_in_years ) ;

   printf( "\n  For a loan of %.2f you must pay "
           "\n  %.2f as compound interest after %d years.\n",
           given_sum_of_money,
           ( given_sum_of_money / 100.0 ) *
           compound_interest_table[ interest_percentage - 5 ]
                                  [ loan_period_in_years - 1 ],
           loan_period_in_years ) ;
}