MakingAnagrams.cs

using System.CodeDom.Compiler;
using System.Collections.Generic;
using System.Collections;
using System.ComponentModel;
using System.Diagnostics.CodeAnalysis;
using System.Globalization;
using System.IO;
using System.Linq;
using System.Reflection;
using System.Runtime.Serialization;
using System.Text.RegularExpressions;
using System.Text;
using System;

class Solution {

    static int makeAnagram(string a, string b)
    {
        var countMap = new int[256];
        
        foreach (var elem in a) countMap[elem]++;
        foreach (var elem in b) countMap[elem]--;
        
        return countMap.Sum(Math.Abs);
    }

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

        string a = Console.ReadLine();

        string b = Console.ReadLine();

        int res = makeAnagram(a, b);

        textWriter.WriteLine(res);

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