C primer plus 第五章编程练习

#include 
#include 
#include
#define HOURS_TO_MINUTES 60
#define DAY_TO_WEEKS 7
#define INCH_TO_CM 0.3937008
#define FEET_TO_CM 0.0328084
#define INCH_TO_FEET 12
void practice5_1(void)
{
    int time;
    int hours, minutes;
    printf("please input time:");
    scanf("%d", &time);

    while(time > 10)
    {
       hours = time / HOURS_TO_MINUTES;
       minutes = time % HOURS_TO_MINUTES;
       printf("hours = %d, minutes = %d\n\n", hours, minutes);
       printf("\n");
       printf("please input time:");
       scanf("%d", &time);

    }
    return;
}

void practice5_2(void)
{
    const int bigger = 10;
    int n, num;
    printf("please input a number:");
    scanf("%d", &num);
    n = num;
    while(n <= num+bigger)
    {
        printf("%d ", n);
        n++;
    }
    printf("\n");

    return;
}

void practice5_3(void)
{
    int days;
    int weeks, day;

    printf("please input convert days:");
    scanf("%d", &days);
    while(days > 0)
    {
        weeks = days / DAY_TO_WEEKS;
        day = days % DAY_TO_WEEKS;
        printf("%d days are %d weeks, %d days\n\n", days, weeks, day);
        printf("please input convert days:");
        scanf("%d", &days);
    }

    return;
}

void practice5_4(void)
{
    float height;
	int feet;
	float inch;

	printf("Enter a height in centimeters: ");
	scanf("%f", &height);
	while(height > 0)
	{
		feet = (int)(height * FEET_TO_CM) ;
		inch = (height * INCH_TO_CM) - (feet * INCH_TO_FEET);
		printf("%.1f cm = %d feet, %.1f inches \n",
		height, feet, inch);
		printf("Enter a height in centimeters (<=0 to quit): ");
		scanf("%f", &height);
	}
	printf("bye \n");

    return;
}

void practice5_5(void)
{
    int day, count, profits;
    profits = 0;
    count = 0;

    printf("please input  days:");
    scanf("%d", &day);
    while(count++ < day)
    {
        profits += count;
    }
    printf("your earn $%d\n", profits);

    return;
}

void practice5_6(void)
{
    int day, count, profits;
    profits = 0;
    count = 0;

    printf("please input  days:");
    scanf("%d", &day);
    while(count++ < day)
    {
        profits += count*count;
    }
    printf("your earn $%d\n", profits);
    return;
}

double practice5_7(double x)
{
    return x*x*x;
}



int main(void)
{
//    practice5_1();
//    practice5_2();
//    practice5_3();
//    practice5_4();
//    practice5_5();
//    practice5_6();
/*    double num;
    double cube;
    printf("Please input a number and ");
	printf("I will give you its cube: \n");
	scanf("%lf", &num);
	cube = practice5_7(num);
	printf("The cube is : %lf: ", cube);
*/

//    practice5_8();
//    practice5_9();

    return 0;
}