Super Reduced String

FRom hackerrank

Steve has a string of lowercase characters in range ascii[‘a’..’z’]. He wants to reduce the string to its shortest length by doing a series of operations. In each operation he selects a pair of adjacent lowercase letters that match, and he deletes them. For instance, the string aab could be shortened to b in one operation.

Steve’s task is to delete as many characters as possible using this method and print the resulting string. If the final string is empty, print Empty String.




           Input

aaabccddd

Output

abd

Solution in C# -

class Solution {

    static string superReducedString(string s) {
        int i = 0;
        for(; i<s.Length-1;)
        {
            if(s[i] == s[i+1])
            {
                if(i<s.Length-2)
                {
                    s = s.Substring(0,i)+s.Substring(i+2);
                    i = 0;
                }
                else
                {
                    s = s.Substring(0,i);
                }
            }
            else
                i++;
        }
    if(string.IsNullOrEmpty(s))
            return "Empty String";
        else
            return s;
    }

    static void Main(string[] args) {
        TextWriter textWriter = new StreamWriter(@System.Environment.GetEnvironmentVariable("OUTPUT_PATH"), true);

        string s = Console.ReadLine();

        string result = superReducedString(s);

        textWriter.WriteLine(result);

        textWriter.Flush();
        textWriter.Close();
    }
}