using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace ConsoleApplication4
{
    class Program
    {
        public static void differentiate(float[,] input)
        {
            if (input.GetLength(1) == 2)
            {
                for(int i = 0; i < input.GetLength(0); i++)
                {
                    if(input[i,1] != 0)
                    {
                        input[i, 0] = input[i, 0] * input[i, 1];
                        input[i, 1] = input[i, 1] - 1;
                    }
                    else
                    {
                        input[i, 0] = 0;
                        input[i, 1] = 0;
                    }
                }
            }
            else
            {
                Console.WriteLine("Length 0 of input array != 2");
            }

        }

        public static void printEq(float[,] eq)
        {
            for (int i = 0; i < eq.GetLength(0); i++)
            {
                if (eq[i, 1] == 0) //if power is 0
                {
                    if (eq[i, 0] != 0)
                    {
                        Console.Write(eq[i, 0]);
                    }
                }
                else if (eq[i, 1] == 1) //if power is 1
                {
                    if (eq[i, 0] == 1) //if coefficient is 1
                    {
                        Console.Write("x");
                    }
                    else
                    {
                        Console.Write(eq[i, 0] + "x");
                    }
                }
                else //if it is another power
                {
                    if (eq[i, 0] == 1) //if coefficient is 1
                    {
                        Console.Write("x^" + eq[i, 1]);
                    }
                    else
                    {
                        Console.Write(eq[i, 0] + "x^" + eq[i, 1]);
                    }
                }

                if (i != (eq.GetLength(0) - 1)) //every term but the last
                {
                    if(eq[i+1,0] != 0)
                    {
                        Console.Write(" + ");
                    }
                }
            }
            Console.WriteLine();
        }

        static void Main(string[] args)
        {
            String input;
            int num;

            do
            {
                Console.WriteLine("How many different powers of x does the equation have?");
                input = Console.ReadLine();
            }
            while (!(Int32.TryParse(input, out num)));

            float[,] eq = new float[num, 2];

            for (int i = 0; i<eq.GetLength(0); i++)
            {
                do
                {
                    Console.WriteLine("Enter the power of x");
                    input = Console.ReadLine();
                }
                while (!(Single.TryParse(input, out eq[i,1])));

                do
                {
                    Console.WriteLine("Enter the coefficient of x^" + eq[i, 1]);
                    input = Console.ReadLine();
                }
                while (!(Single.TryParse(input, out eq[i, 0])));
            }

            printEq(eq);
            differentiate(eq);
            printEq(eq);

            Console.ReadLine();
        }
    }
}