Python 3

def findPoint(px, py, qx, qy):
    # Write your code here
    return [2*qx-px, 2*qy-py]

public static List findPoint(int px, int py, int qx, int qy) {

return Arrays.asList(2 * qx - px, 2 * qy - py);
}

Find the Point sounds like a great challenge for sharpening problem-solving skills! Also, check out vatcal for easy VAT calculations.

Everyone uses midpoint formula, but we can use a different strategy instead:

Notice that to rotate (x, y) around the origin we can use (-x,-y). Now all we have to do is move to the origin, perform reflection, and move back.

Lets employ an algorithm using the coordinates (px, py) and (qx, qy): 1. We move (px,py) and (qx,qy) such that (qx,qy) is at the origin and their distance is maintained. This gives the new coordinates of (px,py) to be (px-qx,py-qy) 2. Now use the rule and multiply by -1, to get (-1 * (px-qx), -1*(py-qy)) 3. Now we go back to the original coordinate by adding back, to get (px + -1 (px-qx), py + -1(py-qy))

Java 15

public static List<Integer> findPoint(int px, int py, int qx, int qy) {
        List<Integer> result = new ArrayList<>();

        int shadowX = (2*qx) - px;
        int shadowY = (2*qy) - py;

        result.add(shadowX);
        result.add(shadowY);

        return result;
    }