Thread: Input Operations Problem

You could ask for the input in your main() function and then pass the input to total_industrial() for it to calculate, rather than doing the actual input inside the total_industrial() function.

What you want to do is ask for the two "extra" inputs as soon as you know that the user is going to do an "industrial" use of the program. I see no better time than in the "I" clause of your makeshift switch statement.

Although I haven't tested this, this should probably get you closer to what you want. I have marked the areas changed.

Code:

#include <stdio.h> /* printf and scanf definitions */
#define RESIDENTIAL_RATE 6.00 /* Rate for residential use */
#define RESIDENTIAL_KWH .052 /* Charge per KWH used for residential */
#define COMMERCIAL_RATE 60.00 /* Rate for commercial use */
#define COMMERCIAL_KWH .045 /* Charge per KWH used for commercial after 1000 */
#define INDUSTRIAL_PEAK_RATE 76.00 /* Rate for industrial use at peak rate  */
#define INDUSTRIAL_PEAK_KWH .065 /* Charge per KWH durign peak rate */
#define INDUSTRIAL_OFF_RATE 40.00 /* Rate for industrial use at off-peak rate */
#define INDUSTRIAL_OFF_KWH .028 /* Charge per KWH during off-peak rate */
#define NOTHING 0 /* Cost for no charge */
/* Function Prototypes */

/* precondition : kw is >= 0
   postcondition : price of bill is returned for residential */

double total_residential(double kw);

/* precondition : kw is >= 0
   postcondition : price of bill is returned for commercial */

double total_commercial(double kw);

/* precondition : kw is >=0
   postcondition : price of bill is returned for industrial */

double total_industrial(double kw,double I_peak_hours, double I_off_peak);  /**** changed to match edit  ***/

int main(void)
{
double kw; /* kilowatts entered by the user */
int account; /*user's account number */
char ans; /* type of use being residential, commercial, or industrial */

/****** Edited ******/
double peak_hours; /* total KWH used at peak hours */
double off_peak; /* total KWH used at off-peak hours */
/******************/

printf("Enter your account number > ");
scanf("%d", &account);
printf("Enter R for residential, C for commercial, or I for industrial use > ");
scanf(" %c", &ans); 
 
printf("Enter the total number of kilowatt-hours used > ");
scanf ("%lf", &kw);
 
if (ans == 'R' || ans == 'r')
   printf("Account %d: Your total bill is $ %6.2f \n\n", account, total_residential(kw));
else if(ans == 'C' || ans == 'c')
   printf("Account %d: Your total bill is $ %6.2f \n\n", account, total_commercial(kw));
else if(ans == 'I' || ans == 'i')
   /*******  Edited  *********/
   printf("Enter the KWH at peak hours > "); 
   scanf("%lf", &peak_hours);
   printf("Enter the KWH at off-peak hours > ");
   scanf("%lf", &off_peak);
   /***********************/
   printf("Account %d: Your total bill is $ %6.2f \n\n", account, total_industrial(kw,peak_hours,off_peak));
else 
   printf("Invalid Use! Did not use R, C, or I. \n\n");

return(0);
}

/* function definitions */
 
double total_residential(double kw)
{
double residential; /* bill for residential */  
if(kw > 0)
  residential = RESIDENTIAL_RATE + (kw * RESIDENTIAL_KWH);
else
  residential = NOTHING;

return(residential);
}

double total_commercial(double kw)
{
double additional_kwh; /* price for each KWH after 1000 */
double commercial; /* bill for commercial use */
additional_kwh = kw - 1000;
   
if(kw < 1000 && kw > 0)
  commercial = COMMERCIAL_RATE;
else if (kw <= 0)
  commercial = NOTHING;
else
  commercial = COMMERCIAL_RATE + (additional_kwh * COMMERCIAL_KWH);
 
return(commercial);
}
 
double total_industrial(double kw,double I_peak_hours, double I_off_peak)    /*** changed some variables in here *****/
{
double industrial; /* bill for industrial use */
double additional_peak; /* price for each KWH at peak hours after 1000 */
double additional_off; /* price for each KWH at off-peak hours after 1000 */
 
additional_peak = I_peak_hours - 1000;
additional_off = I_off_peak - 1000;

if(peak_hours > 1000 && off_peak > 1000)
  industrial = (INDUSTRIAL_PEAK_RATE + (additional_peak * INDUSTRIAL_PEAK_KWH)) + (INDUSTRIAL_OFF_RATE + (additional_off * INDUSTRIAL_OFF_KWH));
else if(I_peak_hours < 1000 && I_peak_hours > 0 && I_off_peak > 1000)
  industrial = (INDUSTRIAL_PEAK_RATE + (INDUSTRIAL_OFF_RATE + (additional_off * INDUSTRIAL_OFF_KWH)));
else if(I_peak_hours < 1000 && I_peak_hours > 0 && I_off_peak < 1000 && I_off_peak > 0)
  industrial = INDUSTRIAL_PEAK_RATE + INDUSTRIAL_OFF_RATE;
else if(I_peak_hours > 1000 && I_off_peak < 1000 && I_off_peak > 0)
  industrial =((INDUSTRIAL_PEAK_RATE + (additional_peak * INDUSTRIAL_PEAK_KWH)) + INDUSTRIAL_OFF_RATE);
else if(I_peak_hours == 0 && I_off_peak > 1000)
  industrial = INDUSTRIAL_OFF_RATE + (additional_off * INDUSTRIAL_OFF_KWH);
else if(I_peak_hours > 1000 && I_off_peak == 0)
  industrial = (INDUSTRIAL_PEAK_RATE + (additional_peak * INDUSTRIAL_PEAK_KWH));
else if(I_peak_hours == 0 && I_off_peak == 0)
  industrial = NOTHING;
else if(I_peak_hours < 1000 && I_peak_hours > 0 && I_off_peak == 0)
  industrial = INDUSTRIAL_PEAK_RATE;
else if(I_peak_hours == 0 && I_off_peak < 1000 && I_off_peak > 0)
  industrial = INDUSTRIAL_OFF_RATE;
return(industrial);
}

Hope this helps.