/*  Distance.c  (c) Kari Laitinen

    http://www.naturalprogramming.com/

    2013-11-19 File created.
    2013-11-19 Last modification.

    Stackoverflow says that we must use format
    specifiers such as %lf, %lg, %le or %la (C99)
    to scanf double values.
*/

#include  <stdio.h>

int main()
{
   double  distance_in_meters,  distance_in_kilometers,
           distance_in_miles,   distance_in_yards,
           distance_in_feet,    distance_in_inches ;
   double  distance_in_light_years ;

   printf( "\n This program converts meters to other units of" 
           "\n distance. Please, enter a distance in meters:  " ) ;

   scanf( "%lf",  &distance_in_meters ) ;

   distance_in_kilometers  =  distance_in_meters / 1000.0 ;
   distance_in_miles       =  6.21371e-4 *  distance_in_meters ;
   distance_in_yards       =  1.093613   *  distance_in_meters ;
   distance_in_feet        =  3.280840   *  distance_in_meters ;
   distance_in_inches      =  12         *  distance_in_feet ;
   distance_in_light_years  =  distance_in_meters /
                               ( 2.99793e8 * 365 * 24 * 3600 ) ;

   printf( "\n %f meters is: \n\n", distance_in_meters ) ;

   printf( "%15.3f  kilometers\n",distance_in_kilometers) ;
   printf( "%15.3f  miles \n",    distance_in_miles ) ;
   printf( "%15.3f  yards \n",    distance_in_yards ) ;

   printf( "%15.3f  feet  \n%15.3f  inches \n",
           distance_in_feet, distance_in_inches ) ;

   printf( "%15.5e  light years \n", distance_in_light_years) ;
}