头文件的使用:

//usehotel.c
#include<stdio.h>
#include "hotel.h"
int main(void)
{
	int nights;
	double hotel_rate;
	int code;
	while((code = menu()) != QUIT)
	{
		switch(code)
		{
		    case 1: hotel_rate = HOTEL1; break;
		    case 2: hotel_rate = HOTEL2; break;
			case 3: hotel_rate = HOTEL3; break;
			case 4: hotel_rate = HOTEL4; break;
			default: hotel_rate = 0.0;
				printf("Oops!\n");
				break;
		}
		nights = getnights();
		showprice(hotel_rate,nights);
	}
	printf("Thank you and goodbye.");
	getchar();
	getchar();
	return 0;
}


//hotel.c
#include<stdio.h>
#include "hotel.h"    
int menu(void)
{
	int code, status;

	printf("\n****************************************\n");
	printf("Enter the number of the desired hotel:\n");
	printf("1) Fairfield Arms 2) Hotel Olympic\n");
	printf("3) Chertworthy Plaza 4) The Stokton\n");
	printf("5) quit\n");
	printf("****************************************\n");
	while((status = scanf("%d", &code)) != 1 || (code < 1 || code > 5))
	{
		if(status != 1)
			scanf("%s*s");
			printf("Enter an integer from 1 to 5, please.\n");
				
	}
	return code;

}

int getnights(void)
{
	int nights;

	printf("How many nights are needed? ");
	while(scanf("%d", &nights) != 1)
	{
		scanf("%*s");
		printf("Please enter an integer,such as 2.\n");
	}
	return nights;
}

void showprice(double rate, int nights)
{
	int n;
	double total = 0.0;
	double factor = 1.0;
	for(n = 1; n <= nights; n++, factor *= DISCOUNT)
	{
		total += rate * factor;
	}
	printf("The total cost will be $%0.2f.\n", total);
}


//hotel.h
#define QUIT	5
#define HOTEL1		80.00
#define HOTEL2		125.00
#define HOTEL3		155.00
#define HOTEL4		200.00
#define DISCOUNT	0.95

int menu(void);

int getnights(void);

void showprice(double,int);

这是代码文件的百度云网址:

https://pan.baidu.com/s/1WSO-9NoHlh4TCkW2iSNINg