using System;

using System.Linq;

public class Program

{

    public static void Main()

    {

        Console.WriteLine("Hello World");

        LargestProductInAGrid();

    }

    public static void LargestProductInAGrid()

    {

            //import number string

        string numberArray = "08 02 22 97 38 15 00 40 00 75 04 05 07 78 52 12 50 77 91 08 49 49 99 40 17 81 18 57 60 87 17 40 98 43 69 48 04 56 62 00 81 49 31 73 55 79 14 29 93 71 40 67 53 88 30 03 49 13 36 65 52 70 95 23 04 60 11 42 69 24 68 56 01 32 56 71 37 02 36 91 22 31 16 71 51 67 63 89 41 92 36 54 22 40 40 28 66 33 13 80 24 47 32 60 99 03 45 02 44 75 33 53 78 36 84 20 35 17 12 50 32 98 81 28 64 23 67 10 26 38 40 67 59 54 70 66 18 38 64 70 67 26 20 68 02 62 12 20 95 63 94 39 63 08 40 91 66 49 94 21 24 55 58 05 66 73 99 26 97 17 78 78 96 83 14 88 34 89 63 72 21 36 23 09 75 00 76 44 20 45 35 14 00 61 33 97 34 31 33 95 78 17 53 28 22 75 31 67 15 94 03 80 04 62 16 14 09 53 56 92 16 39 05 42 96 35 31 47 55 58 88 24 00 17 54 24 36 29 85 57 86 56 00 48 35 71 89 07 05 44 44 37 44 60 21 58 51 54 17 58 19 80 81 68 05 94 47 69 28 73 92 13 86 52 17 77 04 89 55 40 04 52 08 83 97 35 99 16 07 97 57 32 16 26 26 79 33 27 98 66 88 36 68 87 57 62 20 72 03 46 33 67 46 55 12 32 63 93 53 69 04 42 16 73 38 25 39 11 24 94 72 18 08 46 29 32 40 62 76 36 20 69 36 41 72 30 23 88 34 62 99 69 82 67 59 85 74 04 36 16 20 73 35 29 78 31 90 01 74 31 49 71 48 86 81 16 23 57 05 54 01 70 54 71 83 51 54 69 16 92 33 48 61 43 52 01 89 19 67 48";

        int[] intArray = new int[numberArray.Length];

        intArray = ConvertStringArrayToIntArray(numberArray);

        //Console.WriteLine(intArray[3]);

        int[,] twoDArray = new int[20, 20];

        //fill 2d array

        int incrementer = 0;

        for(int i = 0; i < twoDArray.GetLength(0); i++)

        {

            for(int j = 0; j < twoDArray.GetLength(1); j++)

            {

                twoDArray[j, i] = intArray[incrementer];

                incrementer++;

            }

        }

        //Print2DArray(twoDArray);

        int upMax = 0;

        upMax = SolveForUpMaxInArray(twoDArray);

        Console.WriteLine("up max: {0}", upMax);

        //downMax is not needed (made for debug) because this gets products which are equal up and down

        //int downMax = 0;

        //downMax = SolveForDownMaxInArray(twoDArray);

        //Console.WriteLine("down max : {0}", downMax);

        int leftMax = 0;

        leftMax = SolveForLeftMaxInArray(twoDArray);

        Console.WriteLine("left max: {0}", leftMax);

        int leftDiagMax = 0;

        leftDiagMax = SolveForDiagonalLeftMaxInArray(twoDArray);

        Console.WriteLine("left diagonal max : {0}", leftDiagMax);

        int rightDiagMax = 0;

        rightDiagMax = SolveForDiagonalRightMaxInArray(twoDArray);

        Console.WriteLine("right diagonal max : {0}", rightDiagMax);

        int totalMax = FindMaxFromOptions(upMax, leftMax, leftDiagMax, rightDiagMax);

        Console.WriteLine("largest max: {0}", totalMax);

    }

    public static int FindMaxFromOptions(int optionOne, int optionTwo, int optionThree, int optionFour)

    {

        int totalMax = 0;

        int[] optionArray = new int[]{optionOne, optionTwo, optionThree, optionFour};

        totalMax = optionArray.Max();

        return totalMax;

    }

    public static int SolveForDiagonalRightMaxInArray(int[,] array)

    {

        int max  = 0;

        for(int row = 16; row >= 3; row--)

        {

            for(int col = 19; col >= 3; col--)

            {

                int product = 0;

                int numOne = array[col, row];

                int numTwo = array[col - 1, row + 1];

                int numThree = array[col - 2, row + 2];

                int numFour = array[col - 3, row + 3];

                product = numOne * numTwo * numThree * numFour;

                if(max < product)

                {

                    max = product;

                    //debuging

                    /*

                    Console.WriteLine("----------------");

                    Console.WriteLine(numOne);

                    Console.WriteLine(numTwo);

                    Console.WriteLine(numThree);

                    Console.WriteLine(numFour);

                    Console.WriteLine("----------------");

                    */

                }

            }

        }

        return max;

    }

    public static int SolveForDiagonalLeftMaxInArray(int[,] array)

    {

        int max = 0;

        for(int row = 0; row <= 16; row++)

        {

            for(int col = 0; col <= 16; col++)

            {

                int product = 0;

                int numOne = array[col,row];

                int numTwo = array[col+1, row+1];

                int numThree = array[col+2, row+2];

                int numFour = array[col+3, row+3];

                product = numOne * numTwo * numThree * numFour;

                if(max < product)

                {

                    max = product;  

                    //debuging

                    /*

                    Console.WriteLine("----------------");

                    Console.WriteLine(numOne);

                    Console.WriteLine(numTwo);

                    Console.WriteLine(numThree);

                    Console.WriteLine(numFour);

                    Console.WriteLine("----------------");

                    */

                }

            }

        }

        return max;

    }

    public static int SolveForLeftMaxInArray(int [,] array)

    {

        int max = 0;

        for(int row = 0; row <= 19; row++)

        {

            for(int col = 0; col <= 16; col++)

            {

                int product = 0;

                int numOne = array[col,row];

                int numTwo = array[col+1,row];

                int numThree = array[col+2,row];

                int numFour = array[col+3,row];

                //product = array[col, row] * array[col, row + 1] * array[col, row + 2] * array[col, row + 3];

                product = numOne * numTwo * numThree * numFour;

                if(product > max)

                {

                    max = product;

                    //debuging

                    /*

                    Console.WriteLine("----------------");

                    Console.WriteLine(numOne);

                    Console.WriteLine(numTwo);

                    Console.WriteLine(numThree);

                    Console.WriteLine(numFour);

                    Console.WriteLine("----------------");

                    */

                }

            }

        }

        return max; 

    }

    public static int SolveForDownMaxInArray(int[,] array)

    {

        int max = 0;

        for(int i = 0; i <= 15; i++)

        {

            for(int j = 0; j <= 15; j++)

            {

                int temp = array[i,j] * array[i, j + 1] * array[i, j + 2] * array[i, j + 3]; 

                if(temp > max)

                {

                    max = temp; 

                    //debuging

                    /*

                    Console.WriteLine("----------------");

                    Console.WriteLine(array[i,j]);

                    Console.WriteLine(array[i,j + 1]);

                    Console.WriteLine(array[i,j + 2]);

                    Console.WriteLine(array[i,j + 3]);

                    Console.WriteLine("----------------");

                    */

                }

                temp = 0;

            }

        }

        return max;

    }

    public static int SolveForUpMaxInArray(int[,] array)

    {

        int max = 0;

        for(int i = 19; i >= 3; i--)

        {

            for(int j = 19; j >= 3; j--)

            {

                int temp = array[i,j] * array[i,j - 1] * array[i,j - 2] * array[i,j - 3]; 

                if(temp > max)

                {

                    max = temp; 

                    //debuging

                    /*

                    Console.WriteLine(array[i,j]);

                    Console.WriteLine(array[i,j - 1]);

                    Console.WriteLine(array[i,j - 2]);

                    Console.WriteLine(array[i,j - 3]);

                    Console.WriteLine("----------------");

                    */

                }

                temp = 0;

            }

        }

        return max;

    }

    public static void Print2DArray(int[,] array)

    {

        for(int i = 0; i < array.GetLength(0); i++)

        {

            for(int j = 0; j < array.GetLength(1); j++)

            {

                if(array[j,i] < 10)

                {

                    Console.Write("0" + "{0} ", array[j,i]);    

                }

                else

                {

                Console.Write("{0} ", array[j, i]);

                }

            }

            Console.WriteLine('\n');

        }

    }

    public static int[] ConvertStringArrayToIntArray(string array)

    {

        int[] arrayBeingConverted = new int[array.Length];

        string[] numbers = array.Split(' ');

        int i = 0;

        foreach(string number in numbers)

        {

            arrayBeingConverted[i] = Int32.Parse(number);

            //Console.WriteLine(number);

            i++;

        }

        return arrayBeingConverted;

    }

}