Shelf is a kind of data structure which can store elements with the restriction that an element can…

Shelf is a kind of data structure which can store elements with the restriction that an element can be added from the rear end and removed from the front end only. The details of the class Shelf are given below: Class name : Shelf Data members/instance variables: ele[ ] : array to hold decimal numbers lim : maximum limit of the shelf front : to point the index of the front end rear : to point the index of the rear end Methods / Member functions: Shelf(int n ) : constructor to initialize lim=n, front= 0 and rear=0 void pushVal(double v) : to push decimal numbers in the shelf at the rear end if possible, otherwise display the message “ SHELF IS FULL ” double popVal( ) : to remove and return the decimal number from the front end of the shelf if any, else returns −999.99 void display( ) : to display the elements of the shelf

void pushVal(double v)
{
    if (rear == lim)
        System.out.println("SHELF IS FULL");
    else
    {
        ele[rear] = v;
        rear++;
    }
}

double popVal()
{
    if (front == rear)
        return -999.99;
    else
    {
        double v = ele[front];
        front++;
        return v;
    }
}