Untitled

import java.util.Random;

public class Main {
    public static void main(String[] args) {
        Random r = new Random();

        Double[] source = new Double[20];
        for (int i = 0; i < 20; i++) {
            source[i] = 0 + (1) * r.nextDouble();
        }
        Double[] result = new Double[20];
        int tempIndex = 0;
        for (int i = 0; i < 20; i++) {
            if (i % 2 == 0) {
                result[tempIndex] = source[i] + 3;
                tempIndex++;
            }
        }
        for (int i = 0; i < 20; i++) {
            if (result[i] != null)
                System.out.printf("%.5f ", result[i]);
        }
        System.out.print("\n");

//        zad2
        double[] doubleArray = new double[60];
        for (int i=0;i<60;i++){
            doubleArray[i] = i*i + Math.sqrt(i);
        }
        double temp = sumValuesOfCubeIndex(doubleArray);
        System.out.println("Wynik zadania 2" + temp);

//        zad 3
        QuadraticFunction quadraticFunction = new QuadraticFunction(1,1,4,1);
        System.out.println(quadraticFunction);
        quadraticFunction.setX(5);
        System.out.println(quadraticFunction);
    }

    static double sumValuesOfCubeIndex(double[] source) {
        double result = 0;
        for ( int i=0; i<source.length; i++ ){
            if ( isCube(i) )
                result+=source[i];
        }
        return result;
    }

    static boolean isCube(int n) {
        for (int i = 0; i < n; i++) {
            if (i * i * i == n) {
                return true;
            }
            if (i * i * i > n)
                break;
        }
        return false;
    }
}