Question

After doing some intense Googling for a Diamond Problem solver in java, all I could find was the OOP diamond problem. That’s not what I’m after. What I’m looking for is a simple function in java to find the solution to a diamond problem.

A diamond problem can be expressed like this:

A = C * D,

B = C + D

So, if:

A = 10, B = 7

C = 5, D = 2

What I’m attempting to do is solve a diamond problem in java quickly and effectively. I’ve tried nested for loops, but they’re extremely inefficient due to the nature of the program.

If anyone has any ideas, I would love to hear them.

Thanks!

Answer 1

If we observe the following algebra:

B^2 - 4A = (C^2 + 2CD + C^2) - 4CD = (C^2 - 2CD + D^2) = (C-D)^2

Then we can quickly and easily make this function:

public static double[] diamondSolve(double a, double b) {
    double temp = b * b - 4 * a;
    double difference = Math.sqrt(temp); // difference = C - D

    double[] retArray = new double[2];

    // (b + difference) / 2 = (C + D + C - D) / 2 = 2C / 2 = C
    retArray[0] = (b + difference) / 2;

    // B - C = C + D - C  = D
    retArray[1] = b - retArray[0];

    return retArray;
}

By the way, this will generate problems if 4A is bigger than B^2… in that case the answers are imaginary anyway.