#include <iostream>

using namespace std;

class Shape{
public:
    virtual area();
    virtual displayInfo();
    virtual void setSideLength(float);
    virtual void setBase(float);
    virtual void setHeight(float);
};

class Rectangle : public Shape{
private:
    float base;
    float height;
public:
    Rectangle();
    void setBase(float b)
    {
        base = b;
    }
    void setHeight(float h)
    {
        height = h;
    }
    virtual area();
    virtual displayInfo();
    virtual void setSideLength(float);

};

class Circle : public Shape{
private:
    float radius;
public:
    Circle(float r)
    {
        radius = r;
    }
    area();
    displayInfo();
};

class Square : public Rectangle{
public:
    void setSideLength(float s)
    {
        setBase(s);
        setHeight(s);
    }
    area();
    displayInfo();
};

class ShapeListNode{
public:
    Shape *node;
    ShapeListNode *next;
} *sln, *head = NULL;

int main()      //begin main function
{
    char ch = 'i';

    ungetc('\n', stdin); // inject input buffer with a return character

    do
    {
        printf("What kind of shape are you entering?\n");
        printf("\ti: Circle\n");
        printf("\td: Square\n");
        printf("\tp: Rectangle\n");
        printf("\to: Show Collection\n");
        printf("\tq: quit\n");

        flush();                    // flush input buffer
        ch = tolower(getchar());
        branchInsert(ch);
    } while (ch != 113);

    return 0;
}

void flush()            //flush function flushes input buffer
{
    int c;
    do
    {
        c = getchar();
    } while (c != '\n' && c != EOF);
}

void branchInsert(char c)        // menu branch function
{
    switch (c)
    {
    case 'i':   //Circle

        sln = new ShapeListNode();
        float r;

        cout << "Enter the radius: ";
        cin >> r;

        if (head = NULL)
        {
            sln->node = new Circle(r);
            head = sln;
            sln->next = NULL;
        }
        else
        {
            sln->node = new Circle(r);
            sln->next = NULL;
        }
        sln = sln->next;
        break;

    case 'd':   //Square

        sln = new ShapeListNode();
        float s;

        cout << "Enter the side length: ";
        cin >> s;

        if (head = NULL)
        {
            sln->node = new Square();
            sln->node->setSideLength(s);
            head = sln;
            sln->next = NULL;
        }
        else
        {
            sln->node = new Square();
            sln->next = NULL;
        }
        sln = sln->next;
        break;


    case 'p':   //Rectangle

        sln = new ShapeListNode();
        float b, h;

        cout << "Enter the base length: ";
        cin >> b;
        cout << "Enter the height: ";
        cin >> h;

        if (head = NULL)
        {
            sln->node = new Rectangle();
            sln->node->setBase(b);
            sln->node->setHeight(b);
            head = sln;
            sln->next = NULL;
        }
        else
        {
            sln->node = new Rectangle();
            sln->next = NULL;
        }
        sln = sln->next;
        break;


    case 'o':   //Show
        break;

    case 'q':   //Quit
        break;
    default:
        printf("Invalid input\n");      //invalid input
    }
}

void insert