## Algorithm

Problem Name: Can You Access?

In this HackerRank Functions in Java programming problem solution,

You are given a class Solution and an inner class Inner.Private. The main method of class Solution takes an integer num as input. The powerof2 in class Inner.Private checks whether a number is a power of 2 . You have to call the method powerof2 of the class Inner.Private from the main method of the class Solution.

Constraints

1 <= num <= 2 power 30

Sample Input

``````8
``````

Sample Output

``````8 is power of 2
An instance of class: Solution.Inner.Private has been created
``````

## Code Examples

### #1 Code Example with Java Programming

```Code - Java Programming```

``````
import java.io.*;
import java.lang.reflect.*;
import java.util.*;
import java.util.regex.*;
import java.security.*;

public class Solution {
public static void main(String[] args) throws Exception {
DoNotTerminate.forbidExit();
try {
Object o; // Must be used to hold the reference of the instance of the class Solution.Inner.Private
o = new Inner().new Private();
System.out.println(num + " is " + ((Solution.Inner.Private) o).powerof2(num));
System.out.println("An instance of class: " + o.getClass().getCanonicalName() + " has been created");
} // end of try
catch (DoNotTerminate.ExitTrappedException e) {
System.out.println("Unsuccessful Termination!!");
}
} //end of main
static class Inner {
private class Private {
private String powerof2(int num){
return ((num&num-1) == 0) ? "power of 2" : "not a power of 2";
}
}
} // end of Inner
} // end of Solution

class DoNotTerminate { // This class prevents exit(0)
public static class ExitTrappedException extends SecurityException {
private static final long serialVersionUID = 1L;
}

public static void forbidExit() {
final SecurityManager securityManager = new SecurityManager() {
@Override
public void checkPermission(Permission permission) {
if (permission.getName().contains("exitVM")) {
throw new ExitTrappedException();
}
}
};
System.setSecurityManager(securityManager);
}
}
``````
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