《C Primer Plus》第四章

【4.8.1】

# include <stdio.h>
int main()
{
	char last_name[20];
	char first_name[20];

	printf("Please enter your first_name:\n");
	scanf("%s",first_name);
	printf("Please enter your last_name:\n");
	scanf("%s",last_name);
	printf("Your whole name is %s,%s.\n",first_name,last_name);

	return 0;

}

【4.8.2】

# include <stdio.h>
# include <string.h>
int main()
{
	int width;
	char name[40];
	printf("Please enter your name:\n");
	scanf("%s", name);
	printf("\"%s\"\n", name);
	printf("\"%20s\"\n", name);
	printf("\"%-20s\"\n", name);
	width = strlen(name) + 3;
	printf("%*s\n", width, name);
	return 0;
}

【4.8.3】

# include <stdio.h>
int main()
{
	float a;
	printf("Please enter a floating number：\n");
	scanf("%f",&a);
	printf("The input is %f or %.1e\n",a,a);
	printf("The input is +%5.3f or %5.3E\n",a,a);

	return 0;
}

【4.8.4】

# include <stdio.h>
int main()
{
	char name[40];
	float height;

	printf("Hello,what's your name?\n");
	scanf("%s",name);
	printf("How tall are you?\n");
	scanf("%f",&height);
	
	printf("%s,you are %1.3f m tall\n",name,height/100);
	return 0;
}

【4.8.5】

# include <stdio.h>
int main()
{
	float speed,size,time;

	printf("Please enter the speed of download:\n ");
	scanf("%f",&speed);
	printf("Please enter the file size:\n");
	scanf("%f",&size);
	time=(size*8)/speed;
	printf("At %2.2f magabits per second ,a file of %2.2f magabytes download in %2.2f seconed.\n",speed,size,time);

	return 0;
}

【4.8.6】

# include <stdio.h>
# include <string.h>
int main()
{
	char first_name[20],family_name[20];

	printf("Please enter your first_name:\n");
	scanf("%s",first_name);
	printf("Please enter your family_name:\n");
	scanf("%s",family_name);
	printf("%s %s\n",first_name,family_name);
	printf("%*d %*d\n",strlen(first_name),strlen(first_name),strlen(family_name),strlen(family_name));
	printf("%s %s\n",first_name,family_name);
	printf("%-*d %-*d\n",strlen(first_name),strlen(first_name),strlen(family_name),strlen(family_name));

	return 0;
}

【4.8.7】

# include <stdio.h>
# include <float.h>
int main()
{
	double m=1.0/3.0;
	float n=1.0/3.0;
	printf("%.6f  %.12f  %.16f\n",m,m,m);
	printf("%.6f  %.12f  %.16f\n",n,n,n);

	printf("double类型的最少有效数字位数：%d,\nfloat类型的最少有效数字位数：%d\n",DBL_DIG,FLT_DIG);
	

	return 0;
}

【4.8.8】

# include <stdio.h>

# define GALLON 3.785
# define MILE 1.609
int main()
{
	float gallon,mile;

	
	printf("Please enter the miles of the trip:\n");
	scanf("%f",&mile);
	printf("Please enter the amount of the gas:\n");
	scanf("%f",&gallon);
	
	printf("The oil consuption is %.1f mile/gallon.\n",mile/gallon);
	printf("Litre per 100Km:%.1f L.\n",gallon*GALLON/(mile*MILE)*100);

	return 0;
}