using System;
using System.Text;
using System.Collections.Generic;
public class Program
{
public static string GetCommonCharacters(string str1, string str2) {
HashSet<char> commonChars = new HashSet<char>();
foreach (char ch in str1) {
if (ch != ' ' && str2.Contains(ch)) {
commonChars.Add(ch);
}
}
StringBuilder sb = new StringBuilder();
foreach (char ch in commonChars) {
sb.Append(ch);
}
return sb.ToString();
}
public static void Main(string[] args)
{
string str1 = "c c++ c# java go";
string str2 = "python nodejs php javascript";
string strcommon = GetCommonCharacters(str1, str2);
Console.WriteLine("Same letters are: " + strcommon);
}
}
/*
run:
Same letters are: cjavo
*/
