using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace TO2Lab2
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }
        #region
        double a, b, c, d, x0, x, n, limD, limG;
        #endregion
        private void TextBox8_TextChanged(object sender, EventArgs e)
        {

        }

        private void Button1_Click(object sender, EventArgs e)
        {
            textBox6.Clear();
            a = double.Parse(textBox1.Text);
            b = double.Parse(textBox2.Text);
            c = double.Parse(textBox3.Text);
            d = double.Parse(textBox4.Text);

            if (radioButton1.Checked)
            {
                newton();
            }

            else if(radioButton2.Checked)
            {
                falsi();
            }
            else
            {
                textBox6.Text = "Wybierz metodę!";
            }
        }

        private void Button2_Click(object sender, EventArgs e)
        {
            textBox6.Clear();
        }
        public double f(double x)
        {
            return a * Math.Pow(x, 3) + b * Math.Pow(x, 2) + c * x + d;
        }
        public double df(double x)
        {
            return 3 * a * Math.Pow(x, 2) + 2 * b * x + c;
        }

        public void newton()
        {
            x0 = double.Parse(textBox5.Text);
            textBox6.SelectedText = "iteracja\t" + "x\t\t\t" + "f(x)" + Environment.NewLine;
            x = x0;
            for (int i = 0; i <= 25; i++)
            {
                x = x - f(x) / df(x);
                n = n + 1;
                textBox6.SelectedText = i + "\t" + x + "\t" + f(x) + Environment.NewLine;

            }
        }
        public void falsi()
        {
            limD = double.Parse(textBox7.Text);
            limG = double.Parse(textBox8.Text);

            if ((f(limD)*f(limG))>0)
            {
                textBox6.Text = "Błędne granice izolacji pierwiastka!";
            }
            else
            {
                textBox6.SelectedText = "iteracja\t\t" + "x\t" + "limD\t\t\t\t" + "limG" + Environment.NewLine;

                for(int i =1; i < 30; i++)
                {
                    x = limG - f(limG) * (limG - limD) / (f(limG) - f(limD));
                    if(f(x) == 0)
                    {
                        textBox6.Text = x.ToString() + " jest to wartość pierwiastka!";
                    }
                    else if (f(x) * f(limD) < 0)
                    {
                        limG = x;

                    }
                    else if (f(x) * f(limG) < 0)
                    {
                        limD = x;

                    }
                    textBox6.SelectedText = "iteracja;\t\t" + i + "x:\t" + limD + "\t\t" + limG + Environment.NewLine;
                }
            }
    }
    }
}