import java.text.DecimalFormat;

public class Principal {

    public static void main (String[] args){
        Min_Search_Golden_Section(0, 4, 0.1);
    }

    static double f1 (double x){
        return (5+2*(x-3)*(x-3));
    }

    static double f (double x){
        return ((x-2)*(x-2)+4); //Parabola
    }

    static void Min_Search_Golden_Section(double a, double b, double tolerancia){
         double mu = 0.382;  // 1/gama^2
         double x1, x2;
         double fx1, fx2;
         int n = 2; // numero de pontos x calculados
         DecimalFormat df2 = new DecimalFormat(".###");

         x1 = a + mu * (b - a);
         x2 = b - mu * (b - a);
         fx1 = f(x1);
         fx2 = f(x2);

         System.out.println("n\t x1 \t x2 \t a \t b \tf(a) \tf(b)");
         System.out.println(n+"\t"+df2.format(x1)+"\t"+df2.format(x2)+"\t"+df2.format(a)+"\t"+df2.format(b)+"\t"+df2.format(f(a))+"\t"+df2.format(f(b)));

        while ((b - a) > tolerancia && x1<x2) {
            n++;
            if (fx1 > fx2) {
                a = x1; // Descartar intervalo de a a x1
                x1 = x2;
                fx1 = fx2;
                //x2 = b - mu* (b - a); // Determinar novo ponto
                x2 = b + (a-x2);
                fx2 = f(x2);
            } else if (fx2>fx1){
                b = x2; // Descartar intervalo de x2 a b
                x2 = x1;
                fx2 = fx1;
                //x1 = a + mu*(b - a); // Determinar novo ponto
                x1 = a + (b-x1);
                fx1 = f(x1);
            } else {
                n++;
                b = x2; // Descartar intervalo de x2 a b e de a a x1
                a = x1;
                x2 = b - mu * (b - a);
                x1 = a + mu * (b - a);
                fx1 = f(x1);
                fx2 = f(x2);
            }
            System.out.println(n+"\t"+df2.format(x1)+"\t"+df2.format(x2)+"\t"+df2.format(a)+"\t"+df2.format(b)+"\t"+df2.format(f(a))+"\t"+df2.format(f(b)));
        }
        System.out.println("Resultado final "+n+"\t"+df2.format(x1)+"\t"+df2.format(x2)+"\t"+df2.format(f(a))+"\t"+df2.format(f(b)));
    }
}