using System namespace Test class Calc private string firstNum private

using System;

namespace Test
{
    class Calc
    {
        private string firstNum;
        private string secondNum;
        private int[] arrFirstNum;
        private int[] arrSecondNum;
        private int[] result;
        private int[,] resArr;
        private int maxLenOfNum;
        private int minLenOfNum;
        
        public Calc(string fstNum, string scndNum)
        {
            firstNum = fstNum;
            secondNum = scndNum;
            arrFirstNum = new int[firstNum.Length];
            arrSecondNum = new int[secondNum.Length];
            LenCalc();
            resArr = new int[minLenOfNum, firstNum.Length + secondNum.Length];
            result = new int[firstNum.Length + secondNum.Length];
        }

        public bool CheckInput()
        {
            long check;
            if ((!long.TryParse(firstNum, out check)) || (check <= 0) || (!long.TryParse(secondNum, out check)) || (check <= 0))
                return false;
            else
                return true;
        }

        public void Sum()
        {
            int maxIndResArr = (firstNum.Length + secondNum.Length) - 1;

            for (int i = maxIndResArr, k = 1; i >= 0; i--, k++)
            {
                for (int j = 0; j < minLenOfNum; j++)
                    result[i] += resArr[j, i];

                if (result[i] >= 10)
                {
                    int temp = result[i] % 10;
                    result[maxIndResArr - k] = result[maxIndResArr - k] + (result[i] / 10);
                    result[i] = temp;
                }
            }
        }

        public void Multiplication()
        {
            int maxIndResArr = (firstNum.Length + secondNum.Length) - 1;
            int remOfDiv = 0;
            int intPart = 0;
            int lastDigitOfFirstNum = arrFirstNum.Length - 1;

            for (int i = 0; i <= minLenOfNum - 1; i++)
            {
                int lastDigitOfSecondNum = arrSecondNum.Length - 1;

                for (int j = maxIndResArr - i; j >= minLenOfNum - i; j--)
                {
                    RemainderForMulti(out remOfDiv, out intPart, lastDigitOfFirstNum, lastDigitOfSecondNum);
                    resArr[i, j] += remOfDiv;
                    resArr[i, j - 1] += intPart;
                    remOfDiv = 0;
                    intPart = 0;

                    if (resArr[i, j] >= 10)
                    {
                        resArr[i, j - 1] += resArr[i, j] / 10;
                        resArr[i, j] %= 10;
                    }

                    lastDigitOfSecondNum--;
                }

                lastDigitOfFirstNum--;
            }
        }

        public void RemainderForMulti(out int remOfDiv, out int intPart, int i, int j)
        {
            int temp = arrFirstNum[i] * arrSecondNum[j];

            if (temp >= 10)
            {
                remOfDiv = temp % 10;
                intPart = temp / 10;
            }
            else
            {
                remOfDiv = temp;
                intPart = 0;
            }
        }

        public void FillArrs()
        {
            if (long.Parse(firstNum) <= long.Parse(secondNum))
            {
                arrFirstNum = SplitByDigits(firstNum);
                arrSecondNum = SplitByDigits(secondNum);
            }
            else
            {
                arrFirstNum = SplitByDigits(secondNum);
                arrSecondNum = SplitByDigits(firstNum);
            }
        }

        public void LenCalc()
        {
            if (firstNum.Length >= secondNum.Length)
            {
                maxLenOfNum = firstNum.Length;
                minLenOfNum = secondNum.Length;
            }
            else
            {
                maxLenOfNum = secondNum.Length;
                minLenOfNum = firstNum.Length;
            }
        }

        public int[] SplitByDigits(string str)
        {
            int[] arr = new int[str.Length];
            long num = long.Parse(str);
            int i = str.Length - 1;

            while (num != 0)
            {
                arr[i] = (int)num % 10;
                num /= 10;
                i--;
            }

            return arr;
        }

        public string Print2DArray()
        {
            int N = firstNum.Length + secondNum.Length;
            string print = "";

            for (int i = 0; i < minLenOfNum; i++)
            {
                for (int j = 0; j < N - i; j++)
                    print += resArr[i, j] + " ";
                print += Environment.NewLine;
            }

            return print;
        }

        public string PrintArray()
        {
            string print = "";

            foreach (int item in result)
                print += item + " ";

            return print;
        }

    }
}