Sample task and Solution : C++InheritanceAccessing Inherited Functions of HackerRank

 You are given three classes A, B and C. All three classes implement their own version of func.

In class A, func multiplies the value passed as a parameter by :

class A
{
    public:
        A(){
            callA = 0;
        }
    private:
        int callA;
        void inc(){
            callA++;
        }

    protected:
        void func(int & a)
        {
            a = a * 2;
            inc();
        }
    public:
        int getA(){
            return callA;
        }
};

In class B, func multiplies the value passed as a parameter by :

class B
{
    public:
        B(){
            callB = 0;
        }
    private:
        int callB;
        void inc(){
            callB++;
        }
    protected:
        void func(int & a)
        {
            a = a * 3;
            inc();
        }
    public:
        int getB(){
            return callB;
        }
};

In class C, func multiplies the value passed as a parameter by :

class C
{
    public:
        C(){
            callC = 0;
        }
    private:
        int callC;
        void inc(){
            callC++;
        }
    protected:
        void func(int & a)
        {
            a = a * 5;
            inc();
        }
    public:
        int getC(){
            return callC;
        }
};

You are given a class D:

class D 
{

	int val;
	public:
		//Initially val is 1
		 D()
		 {
		 	val = 1;
		 }


		 //Implement this function
		 void update_val(int new_val)
		 {

			
		 }
		 //For Checking Purpose
		 void check(int); //Do not delete this line.
};

You need to modify the class D and implement the function update_val which sets D's val to new_val by manipulating the value by only calling the func defined in classes A, B and C.

It is guaranteed that new_val has only  and  as its prime factors.

Input Format

Implement class D's function update_val. This function should update D's val only by calling A, B and C's func.

Constraints

 new_val 
Note: The new_val only has  and  as its prime factors.

Sample Input

new_val 

Sample Output

A's func will be called once.
B's func will be called once.
C's func will be called once.

Explanation

Initially, val .

A's func is called once:

val = val*2  
val = 2

B's func is called once:

val = val*3
val = 6

C's func is called once:

val = val*5
val = 30

Solution 

#include<iostream>

using namespace std;

class A

{

    public:

        A(){

            callA = 0;

        }

    private:

        int callA;

        void inc(){

            callA++;

        }

    protected:

        void func(int & a)

        {

            a = a * 2;

            inc();

        }

    public:

        int getA(){

            return callA;

        }

};

class B

{

    public:

        B(){

            callB = 0;

        }

    private:

        int callB;

        void inc(){

            callB++;

        }

    protected:

        void func(int & a)

        {

            a = a * 3;

            inc();

        }

    public:

        int getB(){

            return callB;

        }

};

class C

{

    public:

        C(){

            callC = 0;

        }

    private:

        int callC;

        void inc(){

            callC++;

        }

    protected:

        void func(int & a)

        {

            a = a * 5;

            inc();

        }

    public:

        int getC(){

            return callC;

        }

};

class D :public A, public B, public C

{

    int val;

    public:

        //Initially val is 1

         D()

         {

            val = 1;

         }

         //Implement this function

         void update_val(int new_val)

         {

            while (new_val % 5 == 0){

                new_val /= 5;

                C::func(val);

            }

            while (new_val % 3 == 0){

                new_val /= 3;

                B::func(val);

            }

            while (new_val % 2 == 0){

                new_val /= 2;

                A::func(val);

            }

           

         }

         //For Checking Purpose

         void check(int); //Do not delete this line.

};

void D::check(int new_val)

{

    update_val(new_val);

    cout << "Value = " << val << endl << "A's func called " << getA() << " times " << endl << "B's func called " << getB() << " times" << endl << "C's func called " << getC() << " times" << endl;

}

int main()

{

    D d;

    int new_val;

    cin >> new_val;

    d.check(new_val);

}

Source : HackerRank