Factorial dowhile

#include <iostream>
#include <iomanip>
using namespace std;
int main(){
    // factorial starts at 1
    // number = 1 is needed to store term, to multiply the term after another term has been created
    // store stores input to store 1 without affecting input for if
    // final multiplies input with number
    double input, factorial = 1, term, store, number = 1, final;
    cout << "Enter a Number: ";
    cin >> input;
    cout << input << "!" << " is ";
    store = input;
    if (input==0){
        store = 1;
    }
    else if (input!=0){
        do{
            if (factorial<=store - 1){
                //(n - 1) ... (n - (store - 1)
                // stops when factorial <= store - 1
                term = input - factorial;
            }
            //(n - 1)(n - 2) ... stops when factorial <= store - 1
            number *= term;
            factorial++;
        }while (factorial<=store - 1);
    }
    //n(n - 1)(n - 2) ...
    final = store * number;
    cout << setprecision(0) << fixed << final;
}