Mencari Energi kinetik menggunakan rumus ketetepan dan data frekuensi

EnergiKinetik.cpp

#include <iostream>
#include <math.h>

using namespace std;

int main()
{
    int n, counter;
    double penampungNilaiF[n], ek[n];
    double f0 = 5000;
    cout << "Masukkan banyak n : ";
    cin >> n;
    
    for (counter = 0 ; counter < n ; counter++) {
        cout << "Nilai f" << counter+1 << "= ";
        cin >> penampungNilaiF[counter];
        if(penampungNilaiF[counter] < 0) {
            cout << "Nilai f" << counter+1 << "= ";
            cin >> penampungNilaiF[counter];
        }
    }
    
    for (counter = 0 ; counter < n ; counter++) {
        if(penampungNilaiF[counter] < 5000) {
            ek[counter] = 0;
        } else {
            ek[counter] = ((6.63*pow(10, -34) * penampungNilaiF[counter]) - (6.63*pow(10, -34) * f0)) ;
        }
        
        cout << "Nilai Ek" << counter+1 << "= " << ek[counter] << endl;
    }
    

    return 0;
}