C primer plus(第六版）第七章源代码

第七章

/*   7.1   */
#include<stdio.h>
int main(void)
{
   
	const int FREEZING = 0;
	float temperature;
	int cold_days = 0;
	int all_days = 0;
	
	printf("Enter the list of daily low temperature.\n");
	printf("Use Celsius, and enter q to quit.\n");
	while (scanf("%f",&temperature) == 1)
	{
   
		all_days++;
		if (temperature < FREEZING)
			cold_days++;
	} 
	if (all_days != 0)
		printf("%d days total: %.1f%% were below freezing.\n",
			all_days, 100.0 * (float) cold_days / all_days);
	if (all_days == 0)
		printf("No data entered!\n");
		
	return 0;  
} 

/*   7.2   */
#include<stdio.h>
#define SPACE ' '
int main(void)
{
   
	char ch;
	
	ch = getchar();          //读取一个字符 
	while (ch != '\n')       //当一行未结束 
	{
   
		if (ch == SPACE)    //留下空格 
			putchar(ch);    //该字符不变 
		else
			putchar(ch + 1);//改变其他字符 
		ch = getchar();     //获取下一个字符 
	}
	putchar(ch);           //打印换行符 
	
	return 0;
}

/*      7.3      */
#include<stdio.h>
#include<ctype.h>
int main(void)
{
   
	char ch;
	
	while ((ch = getchar()) != '\n')
	{
   
		if (isalpha(ch))    //如果是一个字符 
			putchar(ch + 1); 
		else
			putchar(ch);
	}
	putchar(ch);
	
	return 0;
}

/*    7.4     */
#include<stdio.h>
#define RATE1 0.13230
#define RATE2 0.15040
#define RATE3 0.30025
#define RATE4 0.34025
#define BREAK1 360.0
#define BREAK2 468.0
#define BREAK3 720.0
#define BASE1 (RATE1 * BREAK1)
#define BASE2 (BASE1 + (RATE2 * (BREAK2 - BREAK1)))
#define BASE3 (BASE1 + BASE2 + (RATE3 * (BREAK3 - BREAK2)))