HackerRank: Game Throne - code to study - March 12, 2016

GameThrone2.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.IO;
class Solution {
    static bool isOdd(int n) {
        return 0 != (n % 2);
    }
    
    static void Main(String[] args) {
        /* Enter your code here. Read input from STDIN. Print output to STDOUT. Your class should be named Solution */
        string word = Console.ReadLine();
        Dictionary<char,int> letterCounts = new Dictionary<char,int>();
        foreach (char letter in word.Distinct()) {
            letterCounts[letter] = word.Count(c => letter == c);
        }
        int oddCount = letterCounts.Values.Count(isOdd);
        if (oddCount <= 1) {
            Console.Write("YES");
        } else {
            Console.Write("NO");
        }
    }
}