Secret Message Encoding in C#

One of my friend asked me to write a program that encode a message and make it difficult to understand, kind or secret message.

Message: Hi I am Sunil

First of all there should not be any white space, so our message now looks like “HiIamSunil”. Now we have to make a rectangle form of the message where rows can not be greater than columns.

HiIa

mSun

il

Now the encoded message is “Hmi iSl Iu an”. There should be a white space between every word.

Other examples:

Input: Chillout

Output: Clu hlt io

Input: Good day Sunil

Output: Gdu oan oyi dSl

Here is my solution:

            string str = “Good day Sunil”.Replace(” “, “”);
            int len = str.Length;
            double result = Math.Sqrt(len);
            double numCol = Math.Ceiling(result);
            double numRow = Math.Floor(result);
            int colNo = (int)numCol;
            char[] arr = str.ToCharArray();
            string encodeMsg = string.Empty;
            string temp;
            for (int i = 0; i < colNo; ++i)
            {
                temp = string.Empty;
                for (int j = i; j < len; )
                {
                    temp += arr[j];
                    j += colNo;
                }
                encodeMsg += temp + ” “;
            }
            Console.WriteLine(encodeMsg);
            Console.ReadLine();