Initialize Filter3 Class

#include <iostream>
using namespace std;

// Define Filter3 class here
class Filter3 {
private:
    const int id;
    int coeff[3];
    int lOut;
public:
    Filter3(int fId, int c0, int c1, int c2) 
        : id(fId), coeff{c0, c1, c2}, lOut(0) {}
    
    void apply(int x) {
        lOut = x * coeff[0] + coeff[1] + coeff[2];
    }

    int read() {    
        return lOut; 
    }


};


int main() {
    int id, c0, c1, c2;
    cin >> id >> c0 >> c1 >> c2;

    Filter3 f(id, c0, c1, c2);

    int s1, s2;
    cin >> s1 >> s2;

    f.apply(s1);
    f.apply(s2);

    cout << f.read();
    return 0;
}

hard