Bank domain test - I

1. Write class for the tree structure and method to calculate cummulative sum.

2. What are the rules for Recursion and its drawback ?

3. Suppose I have 10GB text file having numeric values (one per line), on 64 bit JVM with Linux OS, 2 GB RAM and 240 GB Hard disk.

What is most efficient way to find largest number and 10th largest number ?

Can PriorityQueue be a efficient data structure over array of 10 elements, while finding 10th largest number ?

4. Why methods notify(), wait() are provided in Object class not in thread class ?

Written test

1. A class person is given. Person A treated to be greater than Person B, if age of Person A is more than Person B.

If age is same, then natural sorting of name should be used.

Implement standard 2 methods from collection API to sort person list.

public class Person {

  private String name;

  private int age;

  Person(String name, int age) {

      this.name = name;

      this.age = age;

  }

2. What would be the expected output / error / exception and if any error / exception, how to fix it ?

public class IteratorDemo {

    public static void main(String[] args) {

        List list = new ArrayList();

        list.add("XYZ1");

        list.add("XYZ2");

        list.add("XYZ3");

        list.add("XYZ4");

        

        Iterator iterator = list.iterator();

        for (int index = 0; iterator.hasNext(); index++) {

            String next = iterator.next();

            if(next.equals("XYZ2"))

                list.remove(index);

        }

    }

}

3. Write memory implementation of "AgedCache" as per following interface which "evicts" data that is older than a specified period (5 mins.). Cache should remove keys and data which is older than specified period.

public interface Cache {

    void put(Object key, Object value);

    Object get(Object key);

}

Synchronization should be used.

4. Using java 1.4 or below, without third party lib, implement following interface specification for object pool.

public interface Pool {

    Object unpool();

    void pool(Object o);

    int available();

    int allocated();

    int max();

}

Object pool should be client configured with max number of objects that it manages.

5. Describe when this code will be executed, whether it completes or not ? Give proper reasoning.

Note: Stack depth is not unlimited.

public class Recursion {

    public static void main(String[] args) {

        try {

            recurse();

        }

        finally {

            System.out.println("hi");

        }

    }

    

    static void recurse() {

        try{

            recurse();

        }

        finally{

            recurse();

        }

    }

}