Calculating Hypotenuse with C++ Code

[magnifik]

i am trying to write a code that calculates the hypotenuse of a triangle... when i try to run it, i get a run time error. I'm not exactly sure what the problem is.

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

    void hypotenuse(double side1, double side2, double* result)
    {
        *result = sqrt(side1*side1 + side2*side2);
    }

    int main()
    {
        double* p;
        hypotenuse(1.5, 2.0, p);
        cout << "The hypotenuse is " << *p << endl;
    }

 

[Mark44]

I don't see anything obvious, although your main should return a value. What's the run-time error?

 

[magnifik]

nvm, figured it out. i just had to initialize p to new double.

 

[Mark44]

Something like this?

int main()
{
    double answer;
    double* p = &answer;
    hypotenuse(1.5, 2.0, p);
    cout << "The hypotenuse is " << answer << endl;
}

This works for me, and produces the correct result.

 

[magnifik]

i just did

int main()
{
double* p;
p = new double;
hypotenuse(1.5, 2.0, p);
cout << "The hypotenuse is " << *p << endl;
delete [] p; // i know this part is unnecessary though
}

 

[Mark44]

Well, that's one way. At the end you can just delete p since it's not an array.

 

[Mark44]

A much simpler approach is this code in main - no changes needed in hypotenuse:

double answer; 
hypotenuse(1.5, 2.0, &answer);
cout << "Hypotenuse is " << answer << endl;
return 0;

You can initialize answer, but that's not really necessary, since it will be overwritten.