明解C语言入门篇练习题第十二章

练习12-1

#include <stdio.h>

#define NAME_LEN	64		/* 姓名的字符数 */

struct student {
	char  name[NAME_LEN];	/* 姓名 */
	int   height;			/* 身高 */
	float weight;			/* 体重 */
	long  schols;			/* 奖学金 */
};

int main(void)
{
	struct student takao = { "Takao", 173, 86.2 };

	printf("姓名 = %s\n", takao.name);
	printf("身高 = %d\n", takao.height);
	printf("体重 = %.1f\n", takao.weight);
	printf("奖学金 = %ld\n", takao.schols);

	printf("takao.name  的地址是%p\n",&(takao.name));
	printf("takao.height的地址是%p\n", &(takao.height));
	printf("takao.weight的地址是%p\n", &(takao.weight));
	printf("takao.schols的地址是%p\n", &(takao.schols));

	return 0;
}

练习12-2

#include <stdio.h>

#define NAME_LEN	64		/* 姓名的字符数 */

typedef struct student {
	char  name[NAME_LEN];	/* 姓名 */
	int   height;			/* 身高 */
	float weight;			/* 体重 */
	long  schols;			/* 奖学金 */
} Student;

void hiroko(Student *std)
{
	if (std->height < 180) std->height = 180;
	if (std->weight >  80) std->weight = 80;
}

int main(void)
{
	Student sanaka;// = { "Sanaka", 175, 62.5, 73000 };
	printf("input name:");
	scanf("%s",sanaka.name);
	printf("input height:");
	scanf("%d", &(sanaka.height));
	printf("input weight:");
	scanf("%f", &(sanaka.weight));
	printf("input schols:");
	scanf("%ld", &(sanaka.schols));
	hiroko(&sanaka);

	printf("姓名 = %s\n", sanaka.name);
	printf("身高 = %d\n", sanaka.height);
	printf("体重 = %.1f\n", sanaka.weight);
	printf("奖学金 = %ld\n", sanaka.schols);

	return 0;
}

练习12-3

#include <stdio.h>

#define NAME_LEN	64		/* 姓名的字符数 */

struct xyz 
{
	int x;
	long y;
	double z;
};

struct xyz scan_xyz(int x, long y,double z)
{
	struct xyz xyz_value;
	xyz_value.x = x;
	xyz_value.y = y;
	xyz_value.z = z;
	return xyz_value;
}

int main(void)
{
	int x;
	long y;
	double z;
	struct xyz xyz_value;
	printf("input x:");
	scanf("%d",&x);
	printf("input y:");
	scanf("%ld", &y);
	printf("input z:");
	scanf("%lf", &z);
	xyz_value = scan_xyz(x, y, z);
	printf("xyz_value.x = %d\n",xyz_value.x);
	printf("xyz_value.y = %ld\n", xyz_value.y);
	printf("xyz_value.z = %lf\n", xyz_value.z);

	return 0;
}

练习12-4

#include <stdio.h>
#include <string.h>

#define NUMBER		5		/* 学生人数 */
#define NAME_LEN	64		/* 姓名的字符数 */

typedef struct {
	char  name[NAME_LEN];	/* 姓名 */
	int   height;			/* 身高 */
	float weight;			/* 体重 */
	long  schols;			/* 奖学金 */
} Student;

void swap_Student(Student *x, Student *y)
{
	Student temp = *x;
	*x = *y;
	*y = temp;
}

void sort_by_height(Student a[], int n)
{
	int i, j;

	for (i = 0; i < n - 1; i++) {
		for (j = n - 1; j > i; j--)
			if (a[j - 1].height > a[j].height)
				swap_Student(&a[j - 1], &a[j]);
	}
}

void sort_by_name(Student a[], int n)
{
	int i, j;

	for (i = 0; i < n - 1; i++) {
		for (j = n - 1; j > i; j--)
			if (a[j - 1].name > a[j].name)
				swap_Student(&a[j - 1], &a[j]);
	}
}

int main(void)
{
	int i;
	int sort_type;
	Student std[NUMBER];//[] = {
	//	{ "Sato",   178, 61.2, 80000 },	/* 佐藤 */
	//	{ "Sanaka", 175, 62.5, 73000 },	/* 佐中 */
	//	{ "Takao",  173, 86.2, 0 },		/* 高尾 */
	//	{ "Mike",   165, 72.3, 70000 },	/* 平木 */
	//	{ "Masaki", 179, 77.5, 70000 },	/* 真崎 */
	//};
	printf("please input student name,height,weight,schols,use space to separate,use enter to input next student.\n");
	for(i=0;i<NUMBER;i++)
	{ 
		printf("student %d:",i+1);
		scanf("%s %d %f %ld",std[i].name,&(std[i].height),&(std[i].weight),&(std[i].schols));
	}
	printf("\n---------------------------------\n");
	for (i = 0; i < NUMBER; i++)
		printf("%-8s %6d%6.1f%7ld\n",
			std[i].name, std[i].height, std[i].weight, std[i].schols);

	printf("press 0 to sort by height,press 1 to sort by name:");
	scanf("%d",&sort_type);
	switch(sort_type)
	{
		case 0: sort_by_height(std, NUMBER);	/* 按身高进行升序排列 */
				puts("\n按身高排序。");
				for (i = 0; i < NUMBER; i++)
					printf("%-8s %6d%6.1f%7ld\n",std[i].name, std[i].height, std[i].weight, std[i].schols);
				break;
		case 1: sort_by_name(std, NUMBER);	/* 按姓名进行升序排列 */
				puts("\n按姓名排序。");
				for (i = 0; i < NUMBER; i++)
					printf("%-8s %6d%6.1f%7ld\n", std[i].name, std[i].height, std[i].weight, std[i].schols);
				break;
	 }

	return 0;
}

练习12-5

#include <math.h>
#include <stdio.h>

#define sqr(n)  ((n) * (n))

typedef struct {
	double x;	/* X坐标 */
	double y;	/* Y坐标 */
} Point;

typedef struct {
	Point  pt;		/* 当前位置 */
	double fuel;	/* 剩余燃料 */
} Car;

double distance_of(Point pa, Point pb)
{
	return sqrt(sqr(pa.x - pb.x) + sqr(pa.y - pb.y));
}

void put_info(Car c)
{
	printf("当前位置：(%.2f, %.2f)\n", c.pt.x, c.pt.y);
	printf("剩余燃料：%.2f升\n", c.fuel);
}

int move(Car *c, Point dest)
{
	double d = distance_of(c->pt, dest);	/* 行驶距离 */
	if (d > c->fuel)						/* 行驶距离超过了燃料 */
		return 0;							/* 无法行驶 */
	c->pt = dest;		/* 更新当前位置（向dest移动） */
	c->fuel -= d;		/* 更新燃料（减去行驶距离d所消耗的燃料） */
	return 1;								/* 成功行驶 */
}

int main(void)
{
	Car mycar = { { 0.0, 0.0 }, 90.0 };
	int move_method;
	double x_distance;
	double y_distance;
	while (1) {
		int select;
		Point dest;			/* 目的地的坐标 */

		put_info(mycar);	/* 显示当前位置和剩余燃料 */

		printf("开动汽车吗【Yes···1 / No···0】：");
		scanf("%d", &select);
		if (select != 1) break;

		printf("两种方法,1输入目的地,2输入X方向和Y方向的行驶距离:");
		scanf("%d",&move_method);
		switch(move_method)
		{	
			case 1:
				printf("目的地的X坐标：");  scanf("%lf", &dest.x);
				printf("        Y坐标：");  scanf("%lf", &dest.y);
				break;
			case 2:
				printf("X方向行驶距离："); scanf("%lf",&x_distance);
				printf("Y方向行驶距离："); scanf("%lf",&y_distance);
				dest.x = x_distance + mycar.pt.x;
				dest.y = y_distance + mycar.pt.y;
				break;
		}
		if (!move(&mycar, dest))
			puts("\a燃料不足无法行驶。");
	}

	return 0;
}