HackerRank - short palindrome - world codesprint #5 - first try - score 13/40, wrong answer, and also time out issue

shortPalindrom.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace ShortPalindrome
{
    class Program
    {
        static void Main(string[] args)
        {
            //string s = Console.ReadLine(); 
            string s = "abbaab"; 

            Console.WriteLine(getShortPalindrome(s, getAlphabetic(s))); 
        }

        public static void testFunc()
        {
            int[] test1 = getAlphabetic("aaab");

            string test2 = getPseudoString("abcdefac", 'a', 'c'); 

            // test case 1: "011001"  - 4
            
            long count = countingPalindromes("0000001", true);
            count += countingPalindromes("00000011", false); 
        }

        public static int[] getAlphabetic(string s)
        {
            int[] res = new int[26]; 

            if (s == null || s.Length == 0)
                return res;

            string arr = "abcdefghijklmnopqrstuvwxyz";
            int TOTAL = 26;
            int[] noAlph = new int[TOTAL];

            
            char[] aA = arr.ToArray();

            for (int i = 0; i < s.Length; i++)
            {
                int index = s[i] - 'a';
                noAlph[index]++; 
            }

            return noAlph;
        }

        /*
         * 
         */
        public static long getShortPalindrome(string s, int[] input)
        {
            long res = 0; 
            int SIZE = 26;

            long moduleValue = ((long)Math.Pow(10, 9) + 7); 

            for(int i=0; i<SIZE; i++)
            {
                int num = input[i];

                long product = 1; 
                if(num>=4)
                {                    
                    int index = 0; 
                    while(index <=3)
                    {
                        product = (product * (num - index)) % moduleValue;
                        index++; 
                    }

                    product /= 24;
                    res += product % moduleValue;
                }                
            }

            for(int i=0; i<SIZE; i++)
                for(int j=i+1; j<SIZE;j++)
                {
                    int val1 = input[i];
                    int val2 = input[j];

                    if (val1 < 2)
                        break;

                    if (val2 < 2)
                        continue;

                    char chA = (char)(i + 'a');  // bug001 - not val1, should be i, 
                    char chB = (char)(j + 'a');  // bug002 - not val2, should be j

                    string s1 = getPseudoString(s, chA, chB);

                    res += countingPalindromes(s1, true)  % moduleValue;
                    res += countingPalindromes(s1, false) % moduleValue;
                }

            return res; 
        }

        /*
         * using 0 and 1 to construct the string
         * 1001
         * 0110 
         * 
         */
        public static string getPseudoString(string s, char char0, char char1)
        {
            StringBuilder sb = new StringBuilder();             
            
            if (s == null || s.Length == 0)
                return "";

            char[] arr = new char[2] { char0, char1 }; 

            for(int i = 0; i < s.Length; i++)
            {
                char index = s[i]; 

                if(Array.IndexOf(arr, index) != -1)
                {
                    if (index - char0 == 0)
                        sb.Append('0');
                    else
                        sb.Append('1'); 
                }
            }

            return sb.ToString(); 
        }

       
        /*
         * use two loops
         * 
         * get 0110 pairs
         * get 1001 paris 
         * 
         */
        public static long countingPalindromes(string s, bool first0)
        {
            if (s == null || s.Length == 0)
                return 0; 

            int len = s.Length;
            char compare = first0 ? '0' : '1'; 
            char counting = first0 ? '1' : '0'; 

            long count = 0;
            long moduleValue = ((long)Math.Pow(10, 9) + 7); 

            for (int i = 0; i < len; i++ )
                for(int j=i+3; j< len;j++)
            {
                char first = s[i];
                bool firstOne = (first - compare) == 0;
                
                if (!firstOne)
                    break; 

                char second = s[j]; 
                bool secondOne = (second - compare) == 0;

                if (secondOne)
                {
                    // count how many 1 in-between
                    string s1 = s.Substring(i, j-i);
                    int oneC = getCompareCount(s1, counting);
                    
                    count += (oneC * (oneC - 1) / 2) % moduleValue; 
                }
            }

            return count % moduleValue;
        }

        public static int getCompareCount(string s, char compare)
        {
            if (s == null || s.Length == 0)
                return 0;

            int count = 0; 
            for(int i=0; i<s.Length; i++)
            {
                if (s[i] == compare)
                    count++; 
            }

            return count; 
        }

        

    }
}