Vector Program in Java

This Java program is to Implement Vector. The elements of a vector are stored contiguously.Like all dynamic array implementations, vectors have low memory usage and good locality of reference and data cache utilization

Here is the source code of the Java program to implement vector. The Java program is successfully compiled and run on a Linux system. The program output is also shown below.

```
import java.util.ArrayList;
```
```
import java.util.Scanner;
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```
 
```
```
public class Vector<T> 
```
```
{
```
```
    private int capacity;
```
```
    private int size;
```
```
    private ArrayList<T> vector;
```

    private static final int INCREMENT_FACTOR = 5;

```
 
```
```
    public Vector(int size)
```
```
    {
```
```
        this.size = size;
```

        this.capacity = size + INCREMENT_FACTOR;

```
        vector = new ArrayList<T>();
```
```
    }
```
```
 
```

    public void store(int index, T value)

```
    {
```
```
        try 
```
```
        {
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            vector.set(index, value);
```

        } catch (IndexOutOfBoundsException indexOutBounds)

```
        {
```

            if (index >= 0 && (index < size))

```
            {
```

                vector.add(index, value);

```
            }
```

            if (index >= 0 && (index >= size && index < capacity))

```
            {
```

                vector.add(index, value);

```
                size = index + 1;
```
```
                if (size == capacity)
```

                    capacity = capacity + INCREMENT_FACTOR;

```
            }
```
```
            if (index >= capacity)
```
```
            {
```

                throw new IndexOutOfBoundsException();

```
            }
```
```
        }
```
```
    }
```
```
 
```
```
    public T get(int index)
```
```
    {
```
```
        try
```
```
        {
```
```
            return vector.get(index);
```

        } catch (IndexOutOfBoundsException indexOutBounds)

```
        {
```
```
        }
```
```
        return null;
```
```
    }
```
```
 
```
```
    public int getSize()
```
```
    {
```
```
        return size;
```
```
    }
```
```
 
```
```
    public int getCapacity()
```
```
    {
```
```
        return capacity;
```
```
    }
```
```
 
```

    public static void main(String... arg)

```
    {
```
```
        int size;
```
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        int num;
```
```
        int value;
```
```
 
```

        Scanner scanner = new Scanner(System.in);

        System.out.println("Enter the initial size of the vector");

```
        size = scanner.nextInt();
```
```
 
```

        Vector<Integer> vector = new Vector<>(size);

        System.out.println("Enter the number of elements ");

```
        num = scanner.nextInt();
```
```
 
```

        System.out.println("Enter the values");

        for (int index = 0; index < num; index++)

```
        {
```
```
            value = scanner.nextInt();
```
```
            vector.store(index, value);
```
```
        }
```
```
 
```

        System.out.println("The Entered Values are");

        for (int index = 0; index < vector.getSize(); index++)

```
        {
```

            System.out.print(vector.get(index) + "\t");

```
        }
```
```
 
```

        System.out.println("\nTHE SIZE OF THE VECTOR IS  " + vector.getSize());

        System.out.println("THE CAPACITY OF THE VECTOR IS  " + vector.getCapacity());

```
        scanner.close();
```
```
    }
```
```
}
```

$javac Vector.java
$java Vector
 
Enter the initial size of the vector
5
Enter the number of elements 
5
Enter the values
10 9 8 7 6
The Entered Values are
10	9	8	7	6	
THE SIZE OF THE VECTOR IS  5
THE CAPACITY OF THE VECTOR IS  10