package javaapplication1;
import java.util.ArrayList;
import java.util.HashSet;
public class JavaApplication1 {
public static void main(String[] args) {
try {
ArrayList<String> list = new ArrayList<>();
list.add("java");
list.add("c");
list.add("c++");
list.add("c#");
HashSet<String> hash = new HashSet<>();
hash.addAll(list);
if (hash.containsAll(list)) {
System.err.println("yes");
} else {
System.err.println("no");
}
} catch (Exception e) {
System.out.print(e.toString());
}
}
}
/*
run:
yes
*/