Ryspekov's Fibonacci formula C++

#include<iostream>
#include <cmath>
using namespace std;
int zn(int x){
    x=abs(x);
    x+=4;
    x=x/5;
    x=(int)(pow(2.0,x+0.0))%2;
    return x;

}
int main(){
    int n,b;
    double x;
    cin>>b;
    b-=1;
    x=1;
    n=2;
    while(n<b){
         n++;
        int k=(int)(x*(1+sqrt(5))/2);
        x=k+zn(n%3)*(k%2)+(1-zn(n%3))*zn(k%2);
        cout<<(int)(x)<<endl;
    }
    x-=zn(b);
    cout<<x;
    return 0;
}