#include <iostream>
#include <cmath>
using namespace std;

double norm( double x, double y = 0.0, double z = 0.0 );

int main()
{
    cout << "norm(-5.2) = " << norm( -5.2 ) << endl;
    cout << "norm(3.8,-2.5) = " << norm( 3.8, -2.5 ) << endl;
    cout << "norm(3,4.9,-2.35) = " << norm( 3, 4.9, -2.35 ) << endl;
    
    cout << "\n\n"; system( "PAUSE" );
    return( 0 );
}
   
double norm( double x, double y, double z )
{
    double temp, result, max = abs( x );
    if ( max < abs( y ) ) max = abs( y );
    if ( max < abs( z ) ) max = abs( z );
    
    if ( max == 0.0 )
        result = 0.0;
    else {
        temp = pow( x / max, 2 ) + pow( y / max, 2 ) + pow( z / max, 2 );
        result = max * sqrt( temp );
    }
    return( result );
}