수다닷컴

질문 제목 :
아래에 쓰여진코드에 대한 주석좀 달아주세요

수도세를 계산하는 프로그램이라는데잘 모르겠어요....

질문 내용 :
#include stdio.h

#define DEMAND_CHG 35.00
#define PER_1000_CHG 1.10
#define LATE_CHG 2.00

void instruct_water(void);

double comp_use_charge(int previous, int current);

double comp_late_charge(double unpaid);

void display_bill(double late_charge, double bill, double unpaid);

int
main(void)
{
int previous;
int current;
double unpaid;
double bill;
int used;
double use_charge;
double late_charge;
instruct_water();
printf(Enter unpaid balance $);
scanf(%lf, &unpaid);
printf(Enter previous meter reading );
scanf(%d, &previous);
printf(Enter current meter reading );
scanf(%d, ¤t);

use_charge = comp_use_charge(previous, current);
late_charge = comp_late_charge(unpaid);
bill = DEMAND_CHG + use_charge + unpaid + late_charge;
display_bill(late_charge, bill, unpaid);
return (0);
}

void
instruct_water(void)
{
printf(This program figures a water bill );
printf(based on the demand charge\n);
printf(($%.2f) and a $%.2f per 1000, DEMAND_CHG, PER_1000_CHG);
printf(gallons use charge.\n\n);
printf(A $%.2f surcharge is added to , LATE_CHG);
printf(accounts with an unpaid balance.\n);
printf(\nEnter unpaid balance, previous );
printf(and current meter readings\n);
printf(on separate lines after the prompts.\n);
printf(Press return or enter after );
printf(typing each number.\n\n);
}

double
comp_use_charge(int previous, int current)
{
int used;
double use_charge;
used = current - previous;
use_charge = used * PER_1000_CHG;
return (use_charge);
}

double
comp_late_charge(double unpaid)
{
double late_charge;

if (unpaid 0)
late_charge = LATE_CHG;
else
late_charge = 0.0;

return (late_charge);
}

void
display_bill(double late_charge, double bill, double unpaid)
{
if (late_charge 0.0)
{
printf(\nBill includes $%.2f late charge, late_charge);
printf( on unpaid balance of $%.2f\n, unpaid);
}

printf(\nTotal due = $%.2f\n, bill);
}

신청하기