// problem 4

int total = 0;
int numSpecial = 0;                       // count # of special numbers
int num;

cout << "enter a number> ";
cin >> num;

while (num != 0){
    if (num > 0 && IsSpecial(num)){        // check precondition/specialness
	total += num;
	numSpecial++;
    }
    cout << "enter a number> ";
    cin >> num;
}

double avg = 0.0;
if (numSpecial != 0){
    avg = double(total)/numSpecial;
}
cout << "average of special numbers = " << avg << endl;

//-------------------------------------------------------------------------
// problem 5

#include <iostream.h>
#include <math.h>

void GetVitals(double & weight, int & height)
// postcondition: sets weight (kgs) and height (cms)
{
    cout << "enter weight (in lbs.): ";
    cin >> weight;

    weight /= 2.2;            // convert to kilograms

    cout << "enter height (in inches): ";
    cin >> height;

    height *= 2.54;           // convert to centimeters
}

double SurfaceArea(double height, double weight)
// precondition: height and weight given in cms and kgs respectively
// postcondition: returns surface area of person with given height/weight     
{
    return Pow(7.184,-3) * Pow(weight,0.452) * Pow(height,0.725);
}

main()
{
    double weight;
    int height;

    GetVitals(weight,height);
    cout << "your surface area = " << SurfaceArea(height,weight)
	 << " sq. meters" << endl;
}

//-------------------------------------------------------------------------
// several options for finding elements

main()
{

    Element elem(1);                // initialize to something
    String name;
    cout << "enter name of element (control-D to finish): ";
    
    while (cin >> name){
	int k;
	for(k=1; k <= 103; k++){
	    elem.SetAtomic(k);
	    if (elem.Name() == name){
		cout << name << ": number = " << elem.AtomicNumber()
		     << ", weight = " << elem.Weight() << endl;
		break;
	    }
	}
	if (k > 103){
	    cout << name << ": not a recognized element" << endl;
	}
    }
}

// other solution

main()
{

    Element elem(1);                // initialize to something
    String name;
    cout << "enter name of element (control-D to finish): ";
    
    while (cin >> name){
	int k = 0;
	do{
	    k++;
	    elem.SetAtomic(k);
	} while (elem.Name() != name && k < 103);
	
	if (elem.Name() == name){
	    cout << name << ": number = " << elem.AtomicNumber()
		<< ", weight = " << elem.Weight() << endl;
	    break;
	}
	else{
	    cout << name << ": not a recognized element" << endl;	    
	}
    }
}