please using cplusplus amake a accumulator,add function add subtract, multiply and divide and make a demo

Sure, I can help you with that! Here's a C++ code for accumulator, with functions to add, subtract, multiply, and divide:

#include <iostream>
using namespace std;

class Accumulator {
private:
    int value;
public:
    Accumulator(int v = 0) : value(v) {}
    
    int getValue() {
        return value;
    }
    
    void add(int n) {
        value += n;
    }
    
    void subtract(int n) {
        value -= n;
    }
    
    void multiply(int n) {
        value *= n;
    }
    
    void divide(int n) {
        if (n == 0) {
            cout << "Error: Division by zero!" << endl;
            return;
        }
        value /= n;
    }
};

int main() {
    Accumulator acc(10);
    cout << "Value: " << acc.getValue() << endl;
    
    acc.add(5);
    cout << "After adding 5: " << acc.getValue() << endl;
    
    acc.subtract(2);
    cout << "After subtracting 2: " << acc.getValue() << endl;
    
    acc.multiply(3);
    cout << "After multiplying by 3: " << acc.getValue() << endl;
    
    acc.divide(0);
    acc.divide(2);
    cout << "After dividing by 2: " << acc.getValue() << endl;
    
    return 0;
}

This will create an accumulator object `acc` with an initial value of 10. The `getValue()` function returns the current value of the accumulator. The `add()`, `subtract()`, `multiply()`, and `divide()` functions modify the accumulator value accordingly.

In the `main()` function, we demonstrate how to use these functions by adding 5, subtracting 2, multiplying by 3, and dividing by 0 (which will show an error) and 2.

Hope this helps!