Figure 4

Figure 4.1

/* f2c.cpp converts a temperature from Fahrenheit to Celsius,
* using the standard Fahrenheit-to-Celsius conversion formula.
*
* Input: tempFahrenheit
* Output: tempCelsius
********************************************************************/
#include <iostream>
using namespace std;
int main()
{
	cout << "This program converts a temperature\n"
	     <<"from Fahrenheit to Celsius.\n";
	cout <<"\nEnter a Fahrenheit temperature: ";
	double tempFahrenheit;
	cin >> tempFahrenheit;
	double tempCelsius = (tempFahrenheit - 32.0) / 1.8;
	cout << tempFahrenheit << " degrees Fahrenheit is equivalent to "
	     << tempCelsius << " degrees Celsius\n";
}

Sample Runs for Figure 4.1

This program converts a temperature
from Fahrenheit to Celsius.

Enter a Fahrenheit temperature: 212
212 degrees Fahrenheit is equivalent to 100 degrees Celsius


This program converts a temperature
from Fahrenheit to Celsius.

Please enter a Fahrenheit temperature: 32
32 degrees Fahrenheit is equivalent to 0 degrees Celsius

Figure 4.2

/* f2c.cpp converts a temperature from Fahrenheit to Celsius,
* using a conversion function named fahrToCelsius().
*
* Input: tempFahrenheit
* Output: tempCelsius
*******************************************************************/
#include <iostream>
using namespace std;

double fahrToCelsius(double tempFahr); 	// function prototype

int main()
{
	cout << "This program converts a temperature\n"
		<< "from Fahrenheit to Celsius.\n";
	cout << "\nEnter a Fahrenheit temperature: ";
	double tempFahrenheit;
	cin >> tempFahrenheit;
	double tempCelsius = fahrToCelsius(tempFahrenheit);
	cout << tempFahrenheit << " degrees Fahrenheit is equivalent to "
		<< tempCelsius << " degrees Celsius\n";
}

/* fahrToCelsius converts a temperature from Fahrenheit to Celsius.
*
* Receive: tempFahr, a (double) Fahrenheit temperature
* Return: the equivalent Celsius temperature
*******************************************************************/
double fahrToCelsius(double tempFahr) 			// function definition
{
return (tempFahr - 32.0) / 1.8;
}

Figure 4.3

#include <iostream> // cin, cout, <<, >>
using namespace std;
double fahrToCelsius(double tempFahr); // function prototype
int main()
{
	cout << "212F => " << fahrToCelsius(212)
		<< "C\n 32F => " << fahrToCelsius(32)
		<< "C\n";
}

double fahrToCelsius(double tempFahr) // function definition
{
	return (tempFahr - 32.0) / 1.8;
}

Figure 4.5

/* transaction.cpp computes the amount to be returned for a purchase.
*
* Input: purchase, payment
* Output: amount returned to customer (via printAsMoney())
*****************************************************************/
#include <iostream> 			// cin, cout, <<, >>, ...
#include <iomanip> 			// setprecision, ...
using namespace std;

void printAsMoney(double dollars); 	// prototype

int main()
{
	double purchase, 		// amount of purchase
	payment; 			// amount paid
	cout << "Enter amount of purchase: ";
	cin >> purchase;
	cout << "Enter amount paid (>= purchase): ";
	cin >> payment;
	cout << "Amount to return is: ";
	printAsMoney(payment - purchase);
	cout << endl;
}

/* printAsMoney displays an amount in monetary format.
*
* Receive: dollars, the double value to be displayed
* Output: dollars in monetary format
**************************************************************/

void printAsMoney(double dollars)
{
	cout << fixed << showpoint
	<< setprecision(2)
	<< '$' << dollars;
}

Sample Runs for Figure 4.5

Enter amount of purchase: 4.01
Enter amount paid (>= purchase): 5.00
Amount to return is: $0.99


Enter amount of purchase: 9.00
Enter amount paid (>= purchase): 20.00
Amount to return is: $11.00

Figures 4.6 & 4.7

/* driver.cpp is a driver program to test the minimum function.
****************************************************************/
#include <iostream> // cin, cout, <<, >>
using namespace std;

double minimum(double first, double second);

int main()
{
	double num1, num2;
	cout << "Enter two numbers: ";
	cin >> num1 >> num2;
	cout << "Minimum is " << minimum(num1, num2) << endl;
}

/* minimum finds the minimum of two doubles.
*
* Receive: first and second
* Return: the smaller of first and second
************************************************/

double minimum(double first, double second)
{
	if (first < second)
		return first;
	else
		return second;
}

Figures 4.8 & 4.9

/* factDriver.cpp is a driver program to test the factorial function
*
*******************************************************************/
#include <iostream>
using namespace std;
int factorial(int n);

int main()
{
	cout << "To compute n!, enter n: ";
	int theNumber;
	cin >> theNumber;
	cout << theNumber << "! = "
	     << factorial(theNumber) << endl;
}

/* factorial computes the factorial of a nonnegative integer.
*
* Receive: n, an integer
* Precondition: n is nonnegative
* Return: n!
*************************************************************/
#include <cassert> // assert()
using namespace std;

int factorial(int n)
{
	assert(n >= 0);
	int product = 1;
	for (int count = 2; count <= n; count++)
	product *= count;
	return product;
}

Sample Runs for Figure 4.9

To compute n!, enter n: 1
1! = 1

To compute n!, enter n: 2
2! = 2

To compute n!, enter n: 5
5! = 120

To compute n!, enter n: -1
factorial9.cpp:22: failed assertion 'n >= 0'
-1! = Abort

Figure 4.10

/* factorials.cpp is a driver program to test the factorial
* function. It computes any number of factorials.
*
************************************************************/
#include <iostream> // cin, cout, <<, >>
using namespace std;
int factorial(int n);

int main()
{
   int aNumber;
   cout << "To compute n!, enter n (a negative number to quit): ";
   cin >> aNumber;
   while (aNumber >= 0)
   {
	cout << theNumber << "! = "
	     << factorial(aNumber) << "\n\n";
        cout << "Enter next value of n (negative to quit): ";
        cin >> aNumber;
   }
}

Figure 4.12

/* Heat.h provides an interface for a library of
* heat-related constants and functions.
*
* Created by: Jane Roe, August, 2001, at Dooflingy Industries.
* Modification History: Kelvin functions added January 2002 -- JR.
*******************************************************************/
const double HEAT_OF_FUSION = 79.71; 		// calories per gram
const double HEAT_OF_VAPORIZATION = 539.55; 	// calories per gram
double fahrToCelsius(double tempFahr); 		// degrees Celsius
double celsiusToFahr(double tempCels); 		// degrees Fahrenheit
double fahrToKelvin(double tempFahr); 		// degrees Kelvin
double kelvinToFahr(double tempKelv); 		// degrees Fahrenheit
double celsiusToKelvin(double tempCels); 	// degrees Kelvin
double kelvinToCelsius(double tempKelv); 	// degrees Celsius

Figure 4.13

/* Heat.cpp provides the function implementations for Heat,
* a library of heat-related constants and functions.
*
* Created by: Jane Roe, August 2001, at Dooflingy Industries.
* Modification History: Kelvin functions added January 2002 -- JR.
*******************************************************************/

#include "Heat.h"

//---------------------------------------------
double fahrToCelsius(double tempFahr)
{
    return (tempFahr - 32.0) / 1.8;
}

//---------------------------------------------

double celsiusToFahr(double tempCels)
{
    return tempCels * 1.8 + 32.0;
}

// . . . Definitions of other functions omitted to save space . . .

Figure 4.15

/* f2c.cpp converts a temperature from Fahrenheit to Celsius,
* using function fahrToCelsius() that is stored in library Heat.
*
* Input: tempFahrenheit
* Output: tempCelsius
*******************************************************************/
#include <iostream> 		// cin, cout, <<, >>
using namespace std;
#include "Heat.h" 		// our library's header file
int main()
{
	cout << "This program converts a temperature\n"
	     <<"from Fahrenheit to Celsius.\n";
	cout << "\nEnter a Fahrenheit temperature: ";
	double tempFahrenheit;
	cin >> tempFahrenheit;
	double tempCelsius = fahrToCelsius(tempFahrenheit);
	cout << tempFahrenheit << " degrees Fahrenheit is equivalent to "
	     << tempCelsius << " degrees Celsius\n";
}

Figure 4.17

/* Temperature.h provides a Temperature class that (so far)
* provides class methods for temperature conversions.
* ...
*******************************************************************/
#include <cassert> // assert()
using namespace std;

const double MIN_FAHRENHEIT = -459.67,
MIN_CELSIUS = -273.15,
MIN_KELVIN = 0;

class Temperature
{
public:
   static double fahrToCels(double tempFahr);
   static double fahrToKelv(double tempFahr);
   static double celsToFahr(double tempCels);
   static double celsToKelv(double tempCels);
   static double kelvToFahr(double tempKelv);
   static double kelvToCels(double tempKelv);
	// ... other Temperature class method prototypes ...
};

inline double Temperature::fahrToCels(double tempFahr)
{
   assert(tempFahr >= MIN_FAHRENHEIT)
   return (tempFahr - 32.0) / 1.8;
}

inline double Temperature::celsToFahr(double tempCels)
{
   assert(tempCels >= MIN_CELSIUS);
   return tempCels * 1.8 + 32.0;
}

// ... Definitions of other Temperature class methods ...

Figure 4.1

Sample Runs for Figure 4.1

Figure 4.2

Figure 4.3

Sample Run for Figure 4.3

Figure 4.5

Sample Runs for Figure 4.5

Figures 4.6 & 4.7

Sample Run for Figure 4.7

Figures 4.8 & 4.9

Sample Runs for Figure 4.9

Figure 4.10

Figure 4.12

Figure 4.13

Figure 4.15

Figure 4.17