erase the element from a vector.

#include <iostream>
#include <vector>
#include <string>
#include <sstream>
using namespace std;
class Shop
{
    string name;
public:
    Shop() { }
    Shop(string n): name(n) { }
    void getShopName() {cout << name << endl;}
};

class ASubject
{
private:
    vector<Shop* >list;
	/*
		This function is finding the element in the vector
	    if the element is available in the array it return the position( index number )
		of that element.
		if element is not available it return -1.
	*/

    int get_position(Shop *s)
    {
        for(unsigned short  i = 0; i < list.size() ; i++)
        {
            if( list[i] == s )
                return i;
        }
        return -1;
    }
public:
    void attach(Shop *shop)
    {
        list.push_back(shop);
    }

	/*
		for unsubscribe the shop from the notification list.
	*/
    void detach(Shop * shop)
    {
        int index = get_position(shop);
        if (index == -1){
            cout << "element is not found in the list " << endl;
        }
        else
            list.erase(list.begin()+index);

    }
    void notify(float price)
    {
    // todo : notify  function is yet to implement.
    }

    void print_vector()
    {

        /* old style of for loop with stl*/
        //for(unsigned int i = 0 ; i < pe.size() ; i++)
        //    cout << pe[i] << "  " ;

        for(Shop *x : list)
            cout << x << " " << endl; ;
        cout << endl;
    }


};

int main()
{
    ASubject a ;

    Shop s1;
    Shop s2, s3, s4, s5, s6, s7, s8, s9;
    a.attach(&s1); // 0
    a.attach(&s2); // 1
    a.attach(&s3); // 2
    a.attach(&s4); // 3
    a.attach(&s5); // 4
    a.attach(&s6); // 5
    a.attach(&s7); // 6
    a.attach(&s8); // 7

    a.print_vector();

    a.detach(&s5);
    a.print_vector();

    a.detach(&s4);
    a.print_vector();

    a.detach(&s1);
    a.print_vector();

    a.detach(&s8);
    a.print_vector();

    a.detach(&s9);
    a.print_vector();


    return 0;;

}
====================Output====================
sumitmac:RevisionCpp sumit$ ./a.out
0x7ff7b5aa3858
0x7ff7b5aa3830
0x7ff7b5aa3818
0x7ff7b5aa3800
0x7ff7b5aa37e8
0x7ff7b5aa37d0
0x7ff7b5aa37b8
0x7ff7b5aa37a0

0x7ff7b5aa3858
0x7ff7b5aa3830
0x7ff7b5aa3818
0x7ff7b5aa3800
0x7ff7b5aa37d0
0x7ff7b5aa37b8
0x7ff7b5aa37a0

0x7ff7b5aa3858
0x7ff7b5aa3830
0x7ff7b5aa3818
0x7ff7b5aa37d0
0x7ff7b5aa37b8
0x7ff7b5aa37a0

0x7ff7b5aa3830
0x7ff7b5aa3818
0x7ff7b5aa37d0
0x7ff7b5aa37b8
0x7ff7b5aa37a0

0x7ff7b5aa3830
0x7ff7b5aa3818
0x7ff7b5aa37d0
0x7ff7b5aa37b8

element is not found in the list
0x7ff7b5aa3830
0x7ff7b5aa3818
0x7ff7b5aa37d0
0x7ff7b5aa37b8