package kwadratura;

import static java.lang.Math.sqrt;
import java.util.Scanner;

public class Kwadratura {

    private static double myIntegral(double x) {
        // Moja calka
        return (sqrt((x * x) + 0.4)) / (1.2 + sqrt(0.7 * x * x + 1.3));
    }

    private static double solveResult(double downLimitx, double upLimitx, double[][] wielkosciWezlow) {
        double wynikKwadratury = 0;
        /*
        for (int i = 0; i < wielkosciWezlow.length; i++) {
            wynikKwadratury += wielkosciWezlow[i][1] * myIntegral(((upLimitx - downLimitx) / 2) * wielkosciWezlow[i][0] + ((upLimitx + downLimitx) / 2));
        }*/
        for (double[] wielkosciWezlow1 : wielkosciWezlow) {
            wynikKwadratury += wielkosciWezlow1[1] * myIntegral((((upLimitx - downLimitx) / 2) * wielkosciWezlow1[0]) + ((upLimitx + downLimitx) / 2));
        }
        wynikKwadratury = ((upLimitx - downLimitx) / 2) * wynikKwadratury;
        return wynikKwadratury;
    }

    public static void main(String[] args) {

        double downLimit = 1.3, upLimit = 2.5, wynikKwadraturyGaussa = 0;
        int choosedN;
        System.out.println("Wybierz n: ");
        Scanner scanner = new Scanner(System.in);
        choosedN = scanner.nextInt();
        if (choosedN == 2) {
            double[][] wielkosciWezlow
                    = {{0.57735027, 1.0},
                    {-0.57735027, 1.0}};
            wynikKwadraturyGaussa = solveResult(downLimit, upLimit, wielkosciWezlow);
        } else if (choosedN == 4) {
            double[][] wielkosciWezlow
                    = {{0.33998104, 0.65214515},
                    {-0.33998104, 0.65214515},
                    {0.86113631, 0.34785485},
                    {-0.86113631, 0.34785485}};
            wynikKwadraturyGaussa = solveResult(downLimit, upLimit, wielkosciWezlow);
        } else if (choosedN == 3) {
            double[][] wielkosciWezlow
                    = {{0.0, 0.88888889},
                    {0.77459667, 0.55555555},
                    {-0.77459667, 0.55555555}};
            wynikKwadraturyGaussa = solveResult(downLimit, upLimit, wielkosciWezlow);
        } else if (choosedN == 5) {
            double[][] wielkosciWezlow
                    = {{0.0, 0.56888889},
                    {0.53846931, 0.47862867},
                    {-0.53846931, 0.47862867},
                    {0.90617985, 0.23692689},
                    {-0.90617985, 0.23692689}};
            wynikKwadraturyGaussa = solveResult(downLimit, upLimit, wielkosciWezlow);
        } else if (choosedN == 6) {
            double[][] wielkosciWezlow
                    = {{0.23861918, 0.46791393},
                    {-0.23861918, 0.46791393},
                    {0.66120939, 0.36076157},
                    {-0.66120939, 0.36076157},
                    {0.93246951, 0.17132449},
                    {-0.93246951, 0.17132449}};
            wynikKwadraturyGaussa = solveResult(downLimit, upLimit, wielkosciWezlow);
        } else if (choosedN == 7) {
            double[][] wielkosciWezlow
                    = {{0.0, 0.41795918},
                    {0.40584515, 0.38183005},
                    {-0.40584515, 0.38183005},
                    {0.74153119, 0.27970539},
                    {-0.74153119, 0.27970539},
                    {0.94910791, 0.12948497},
                    {-0.94910791, 0.12948497}};
            wynikKwadraturyGaussa = solveResult(downLimit, upLimit, wielkosciWezlow);

        } else if (choosedN == 8) {
            double[][] wielkosciWezlow
                    = {{0.18343464, 0.36268378},
                    {-0.18343464, 0.36268378},
                    {0.52553241, 0.31370665},
                    {-0.52553241, 0.31370665},
                    {0.79666648, 0.22238103},
                    {-0.79666648, 0.22238103},
                    {0.96028986, 0.10122854},
                    {-0.96028986, 0.10122854}};
            wynikKwadraturyGaussa = solveResult(downLimit, upLimit, wielkosciWezlow);
        } else if (choosedN == 9) {
            double[][] wielkosciWezlow
                    = {{0.0, 0.33023936},
                    {0.32425342, 0.31234708},
                    {-0.32425342, 0.31234708},
                    {0.61337143, 0.26061070},
                    {-0.61337143, 0.26061070},
                    {0.83603111, 0.18064816},
                    {-0.83603111, 0.18064816},
                    {0.96816024, 0.08127439},
                    {-0.96816024, 0.08127439}};
            wynikKwadraturyGaussa = solveResult(downLimit, upLimit, wielkosciWezlow);
        } else if (choosedN == 10) {
            double[][] wielkosciWezlow
                    = {{0.14887434, 0.29552422},
                    {-0.14887434, 0.29552422},
                    {0.43339539, 0.26926672},
                    {-0.43339539, 0.26926672},
                    {0.67940957, 0.21908636},
                    {-0.67940957, 0.21908636},
                    {0.86506337, 0.14945135},
                    {-0.86506337, 0.14945135},
                    {0.97390653, 0.06667134},
                    {-0.97390653, 0.06667134}};
            wynikKwadraturyGaussa = solveResult(downLimit, upLimit, wielkosciWezlow);
        } else {
            System.out.println("Podales zly N - Prosze, wybierz inny");
        }
        System.out.println("Wynik calki: " + wynikKwadraturyGaussa);
    }

}