C#_面试

   class Program
    {
        static void Main(string[] args)
        {
            int[] arr = { 12, 34, 6, 22, 8 };
            var arry = ConvertSum(arr);

            int[] num = { 1, 2, 3, 4, 5, 6 };
            SetNum(num);
            SetNum();
        }

        //冒泡排序，目的：按从小到大排序，比较相邻两个元素，如果左边元素大于右边元素，则交换
        public static int[] ConvertSum(int[] arry)
        {
            int temp = -1;
            for (int i = arry.Length; i > 0; i--)
            {
                for (int j = 0; j < i - 1; j++)
                {
                    if (arry[j] > arry[j + 1])
                    {
                        temp = arry[j];
                        arry[j] = arry[j + 1];
                        arry[j + 1] = temp;
                    }
                }
            }
            return arry;
        }

        //1、要求是用OO的思想处理20位以内整数的乘法（解释器模式）
        public static void SetNum(int[] num)
        {
            var temp = 0;
            for (int i = 0; i < num.Length; i++)
            {
                if (i < num.Length - 1)
                {
                    if (temp == 0)
                        temp += num[i] * num[i + 1];
                    else
                        temp += temp * num[i];
                }
            }
            Console.WriteLine(temp);
        }

        //2、11个9 乘以  11个9   等于9999.........01   写个算法的
        /// <summary>
        //  125
        //x  11
        //-------
        //  125
        // 125
        //--------
        // 1375
        //将乘数每位与乘数相乘，获取到一个m*n的矩阵
        //将矩阵错位相加，得到输出数组
        //对输出中数组进行进位运算
        /// </summary>
        /// <param name="num1"></param>
        /// <param name="num2"></param>
        public static void SetNum(string num1 = "99999999999", string num2 = "99999999999")
        {
            var input1 = num1.Select(i => (int)(i - ‘0‘));
            var input2 = num2.Select(i => (int)(i - ‘0‘));

            //把num1依次和num2每位相乘，获取到一个m*n的矩阵
            var rectangel = input2.Select(i => input1.Select(j => j * i).ToArray()).ToArray();

            //将矩阵错位相加，得到输出数组
            var result = new int[num1.Length + num2.Length];
            for (int row = 0; row < num2.Length; row++)
            {
                for (int column = 0; column < num1.Length; column++)
                {
                    result[column + row + 1] += rectangel[row][column];
                }
            }

            //对输出中数组进行进位运算
            for (int i = result.Length - 1; i >= 0; i--)
            {
                if (result[i] < 10)
                    continue;

                result[i - 1] += result[i] / 10;
                result[i] %= 10;
            }

            Console.WriteLine(new string(result.Select(i => (char)(i += ‘0‘)).ToArray()));
        }

    }