Another Casual Coder

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
namespace DailyCodingProblem
{
 /*
 Good morning!
 Here's a solution to yesterday's problem.
 This is your coding interview problem for today.
 This problem was asked by Amazon.
 Run-length encoding is a fast and simple method of encoding strings. The basic idea is to represent repeated successive characters as a single count and character. For example, the string "AAAABBBCCDAA" would be encoded as "4A3B2C1D2A".
 Implement run-length encoding and decoding. You can assume the string to be encoded have no digits and consists solely of alphabetic characters. You can assume the string to be decoded is valid.
 We will be sending the solution tomorrow, along with tomorrow's question. As always, feel free to shoot us an email if there's anything we can help with.
 Have a great day!
 */
 class DailyCodingProblem10132018
 {
 public string RunLengthEncode(string str)
 {
 if (String.IsNullOrEmpty(str) || str.Length == 1) return str;
 string retVal = "";
 int count = 1;
 for (int i = 1; i < str.Length; i++)
 {
 if (str[i] == str[i - 1]) count++;
 else
 {
 if (count > 1) retVal += count.ToString();
 retVal += str[i - 1].ToString();
 count = 1;
 }
 }
 if (count > 1) retVal += count.ToString();
 retVal += str[str.Length - 1].ToString();
 return retVal;
 }
 }
}