C++ Primer Plus Chapter3

C++ Primer Plus Chapter3

//3.1
#include<iostream>
int main()
{
using namespace std;
int height, feet, inches;
cout << "Enter your height(inches) ____\b\b\b\b";
cin >> height;
const int con_fac = 12;
feet = height / con_fac;
inches = height % con_fac;
cout << "Your heght is " << feet << " feet and " << inches << " inches" << endl;
return 0;
}

//3.2
#include<iostream>
int main()
{
using namespace std;
int feet, inches;
double weight;
cout << "Enter your height's feet,inches and weight(pound)" << endl;
cin >> feet >> inches >> weight;
const int con_fac_h = 12;
const double con_fac_i = 0.0254;
const double con_fac_w = 2.2;
double height = feet * con_fac_h + inches;
height = con_fac_i*height;
weight = weight / con_fac_w;
double BMI = weight / (height*height);
cout << "BMI=" << BMI << endl;
return 0;
}

//3.3
#include<iostream>
int main()
{
using namespace std;
int degrees, minutes, seconds;
const double con_fac = 60;//转换因子
cout << "Enter a latitude in degrees,minutes,and seconds:" << endl;
cout << "First, enter the degrees:___\b\b\b";
cin >> degrees;
cout << "Next, enter the minutes of arc:___\b\b\b";
cin >> minutes;
cout << "Finally, enter the seconds of arc:___\b\b\b";
cin >> seconds;
cout << degrees << " degrees, " << minutes << " minutes, " << seconds << " seconds = ";
cout << degrees * 1 + minutes / con_fac + seconds / con_fac / con_fac << "degrees." << endl;
return 0;
}

//3.4
#include<iostream>
int main()
{
using namespace std;
long seconds;
cout << "Enter the number of seconds:";
const int con_day = 24, con_hour = 60, con_minutes = 60;
cin >> seconds;
int second = seconds % con_minutes;
int minutes = seconds / con_minutes%con_hour;
int hours = seconds / con_minutes / con_hour%con_day;
int days = seconds / con_minutes / con_hour / con_day;
cout << seconds << "seconds = " << days << " days, " << hours << " hours, ";
cout << minutes << " minutes, " << second << " second." << endl;
return 0;
}

//3.5
#include<iostream>
int main()
{
using namespace std;
float wor, ame;
cout << "Enter the world's population:";
cin >> wor;
cout << "Enter the population of the US:";
cin >> ame;
float per = ame / wor;
cout << "The population of the US is " << per*100 << "% of the world population." << endl;
return 0;
}

//3.6
#include<iostream>
int main()
{
using namespace std;
float km, l;
cout << "Enter the distance of driving(Km):";
cin >> km;
cout << "Enter the gasoline usage(L):";
cin >> l;
cout << "The fuel consumption per 100 kilometers is " << km / l / 100;
return 0;
}