Needing help to reduce the damge_bar of the ship (Beginner)

I'm needing help with this code. The idea is that I has a ship and if I hit it with a shoot the health bar will go from 100 and down until it is 0 then the ship doesn't exists anymore. But I have problem while saying to the program that if it was a hit do "health_bar -= 10" I know what the problem are but not how to fix it. Is it anyone that has another idea of doing this or how to do this?. Please help!.

Code:

---

#include <iostream>
#include <cstddef>
#include <cstdlib>


using namespace std;


class Ships
{
    public:
        int health_bar;
        string name;
};


Ships* getNewShip()
{
    Ships *p_ship = new Ships;
    p_ship->name = " ";
    p_ship->health_bar = 0;
    return p_ship;
}


void Ship_1()
{
    Ships *p_ship;
    p_ship->name = "Xtr-30";
    p_ship->health_bar += 100;
    cout << "Name: " << p_ship->name << endl;
    cout << "Health: " << p_ship->health_bar << endl;
}


int main()
{
bool menu = false;


while (menu == false)
{
    system("CLS");
    int input;


    cout << "Attack ship: ";
    cin >> input;


    if (input == 1)
    {
        Ships* getShip = getNewShip();
        Ship_1(getShip);
        system("PAUSE");
    }
}
    return 0;
}

---

Where is your attempt for the action you want to perform, captain? :)

The code won't even compile.
Also,
>>Ships *p_ship = new Ships;
Just don't do that. Just do
Ships p_ship;
then work with that. Return it if you want, even.

Allocating with new is discouraged unless you absolutely have to (and I see no reason for doing so).
See dynamic memory management if you want to learn about this topic (it can be quite advanced, so avoid it unless necessary; simplicity is best).

Thanks got it work now! :)