#include <stdio.h>

#include "fuel.h"

float avarage_fuel_per_mile (int miles_one_year_ago,
                             int miles_today,
                             int liters) {

  int miles = miles_today - miles_one_year_ago;

  float liters_per_mile;
  if (miles == 0 && liters == 0) {
    liters_per_mile = 0;
  }
  else {
    liters_per_mile = liters/(float)miles;
  }

  return liters_per_mile;
}