using System;

using System.Diagnostics;

using System.Drawing;

namespace ConsoleApp1

{

class Program

    {

static void Main(string[] args)

        {

Console.Write("a="); double a = Convert.ToDouble(Console.ReadLine());

Console.Write("b="); double b = Convert.ToDouble(Console.ReadLine());

Console.Write("c="); double c = Convert.ToDouble(Console.ReadLine());

Console.Write("d="); double d = Convert.ToDouble(Console.ReadLine());

double range = 20;

double x = -range, dx = 0.000002, y1, y2, p = 0, dp, minY=Double.MaxValue, maxY=Double.MinValue;

            y1 = a * x * x * x + b * x * x + c * x + d;

            y2 = y1;

Stopwatch sw = new Stopwatch();

            sw.Start();

while (x < range)

            {

                y1 = a * x * x * x + b * x * x + c * x + d;

if (y1 * y2 < 0)

Console.WriteLine($"x={x}");

                y2 = y1;

if (y1 > maxY)

                    maxY = y1;

if (y1 < minY)

                    minY = y1;

                dp = (y1 + y2) * dx / 2;

if (dp < 0)

dp = -dp;

                p += dp;

                x += dx;

}

            sw.Stop();

Console.WriteLine($"pole={p} " + sw.Elapsed);

Bitmap bmp = new Bitmap(1000, 750);

Graphics gr = Graphics.FromImage(bmp);

Pen pen = new Pen(Color.Black);

Pen pr = new Pen(Color.Red);

            gr.FillRectangle(new SolidBrush(Color.White), 0, 0, bmp.Width, bmp.Height);

            gr.DrawLine(pen, 0, bmp.Height / 2, bmp.Width, bmp.Height / 2);

            gr.DrawString($"{range}", new Font(FontFamily.GenericSansSerif, 18), new SolidBrush(Color.Red),

new Point(0, bmp.Height / 2));

// gr.DrawLine(pen, 0, bmp.Height / 2, bmp.Width, bmp.Height / 2);

double scaleY = bmp.Height / (maxY - minY);

double scaleX = bmp.Width / (2 * range);

            x = -range;

            y1 = a * x * x * x + b * x * x + c * x + d;

            y2 = y1;

            dx = 2*range / bmp.Width;

while (x < range)

            {

                y1 = a * x * x * x + b * x * x + c * x + d;

                gr.DrawLine(pr, (int) (bmp.Width / 2 + (x-dx) * scaleX), (int) (bmp.Height / 2 - y2 * scaleY),

                    (int) (bmp.Width / 2 + x * scaleX), (int) (bmp.Height / 2 - y1 * scaleY));

                y2 = y1;

                x += dx;

            }

            bmp.Save("bmp.png");

Console.ReadLine();

        }

    }

}