C++ Primer Plus 第六版（中文版）课后编程题----第三章

3.1：

#include <iostream>
using namespace std;

#define  c 12

int main()
{
	int cun;
	cout << "你的身高是____英寸？" << endl;
	cin >> cun;
	int a, b;
	a = cun / c;
	b = cun%c;

	cout << "你的身高转换之后为 " << a << " 英尺，" << b << " 英寸。" << endl;

	cin.get();
	cin.get();

	return 0;
}

3.2：

#include <iostream>
using namespace std;

#define FEETtoINCH 12
#define INCHtoMILE 0.0254
#define KGtoPOUND 2.2

int main()
{
	int feet, inch;
	float pound, mile, kg, ibm;
	cout << "请输入你的身高：__英尺__英寸。" << endl;
	cin >> feet >> inch;
	cout << "请输入你的体重：__磅。" << endl;
	cin >> pound;

	mile = INCHtoMILE*float(feet*FEETtoINCH + inch);
	kg = pound / KGtoPOUND;
	ibm = kg / (mile*mile);

	cout << "你的体重指数为：" << ibm << endl;

	cin.get();
	cin.get();
	return 0;
}

3.3

#include <iostream>
using namespace std;

#define T 60

int main()
{
	int degree, second, minute;
	double degree_d;

	cout << "Enter a latitude in degrees, minutes and seconds:" << endl
		<< "First, enter the degrees:";
	cin >> degree;
	cout << "Next, enter the minutes of arc:";
	cin >> minute;
	cout << "Finally, enter the seconds of arc:";
	cin >> second;

	degree_d = double(degree) + double(minute) / T + double(second) / T / T;
	
	cout << degree << " degrees, " << minute << " minutes, " << second << " seconds = " << degree_d << " degrees" << endl;

	cin.get();
	cin.get();
	return 0;
}

3.4

#include <iostream>
using namespace std;

#define T 60
#define D 24

int main()
{
	long long seconds;
	long long temp;
	int day, hour, minu, sec;

	cout << "Enter the number of seconds: ";
	cin >> seconds;

	sec = seconds%T;
	temp = seconds / T;
	minu = temp%T;
	temp = temp / T;
	hour = temp%T;
	temp = temp / D;
	day = temp;

	cout << seconds << " seconds = " 
		<< day << " days, " 
		<< hour << " hours, " 
		<< minu << " minutes, " 
		<< sec << " seconds." << endl;

	cin.get();
	cin.get();
	return 0;
}

3.5

#include <iostream>
using namespace std;

int main()
{
	long long Population_USA, Population_world;
	double ratio;

	cout << "Enter the world's population: ";
	cin >> Population_world;
	cout << "Enter the population of the US: ";
	cin >> Population_USA;

	ratio = (double(Population_USA)) / (double(Population_world)) * 100;
	cout << "The population of the US is " << ratio << "% of the world population." << endl;

	cin.get();
	cin.get();
	return 0;
}

3.6

#include <iostream>
using namespace std;

#define LEN 1.609344		//1 英里 = 1.609344 千米
#define VOLUME 3.7854118	//1 美式加仑 = 3.7854118 升

int main()
{
	double mile, gallon;

	cout << "请输入以英里为单位的里程数：";
	cin >> mile;
	cout << "请输入以加仑为单位的汽油量：";
	cin >> gallon;

	cout << "美国风格的耗油量为：每加仑 " << (double(mile)) / (double(gallon)) << " 英里。" << endl;
	cout << "欧洲风格的耗油量为：每 100 公里的耗油量为：" << (double(gallon*VOLUME)) / (double(mile*LEN)) * 100 << "升。" << endl;

	cin.get();
	cin.get();
	return 0;
}

3.7

#include <iostream>
using namespace std;

#define TO (62.14*3.875)

int main()
{
	float mpg;

	cout << "请输入美国风格的耗油量（每加仑多少英里）：";
	cin >> mpg;
	cout << mpg << "mpg 对应的欧洲风格的耗油量为：" << TO / mpg << "/100km" << endl;
	
	cin.get();
	cin.get();
	return 0;
}