my interpretation of FFT radix-4 N=4 algorithm c++ source code

//https://www.beechwood.eu/fft-implementation-r2-dit-r4-dif-r8-dif/
//my interpretation of FFT radix-4 algorithm c++ source code it works witch
// FFT=+/-cos(w+fi)-isin(w+fi) and maybe witch other functions that are mirror inverse
//author marcin matysek (r)ewertyn.PL
#include <iostream>
#include "conio.h"
#include <stdlib.h>
#include <math.h>
#include <complex>
#include <fstream>
using namespace std;

void fun_fourier_transform_DFT_method5_full_complex(int N,std::complex<double> tab[]);
void fun_fourier_transform_FFT_radix_4_N_4(int N,std::complex<double> tab[]);

int b1,b2,b3;

int main()
{
    std::complex<double>tab2[4]={};
    std::complex<double>tab3[4]={};

    std::fstream plik;

    plik.open("test.txt", std::ios::in | std::ios::out);

/*
    if( plik.good() == false )
    {

        cout<<"create file : test.txt"<<endl;
        system("pause");

    }
*/

    int N=4;

    for(int i=0;i<4;i++)
    {
        tab2[i].real()=i*1.2+1;
        tab2[i].imag()=i*3.2+1;
        tab3[i].real()=i*1.2+1;
        tab3[i].imag()=i*3.2+1;
    }


    cout<<endl;
cout<<"signal g(x)"<<endl;
    for(int j=0;j<N;j++)
    {
    cout.precision(4);
    cout<<round(tab2[j].real()*1000)/1000<<"  ";
    }

    cout<<endl;
    cout<<endl;
    for(int j=0;j<N;j++)
    {
    cout.precision(4);
    cout<<round(tab2[j].imag()*1000)/1000<<"  ";
    }
    cout<<endl;
    cout<<endl;
cout<<"signal g(x)"<<endl;
    for(int j=0;j<N;j++)
    {
    cout.precision(4);
    cout<<round(tab3[j].real()*1000)/1000<<"  ";
    }

    cout<<endl;
    cout<<endl;
    for(int j=0;j<N;j++)
    {
    cout.precision(4);
    cout<<round(tab3[j].imag()*1000)/1000<<"  ";
    }
    cout<<endl;
    cout<<endl;


    for(int i1=0;i1<2;i1++)
    {
        if(i1==0){b1=0;}
        if(i1==1){b1=1;}
    for(int i2=0;i2<2;i2++)
    {
        if(i2==0){b2=0;}
        if(i2==1){b2=1;}
    for(int i3=0;i3<2;i3++)
    {
        if(i3==0){b3=0;}
        if(i3==1){b3=1;}


    for(int i=0;i<4;i++)
    {
        tab2[i].real()=i*1.2+1;
        tab2[i].imag()=i*3.2+1;
        tab3[i].real()=i*1.2+1;
        tab3[i].imag()=i*3.2+1;
    }


    fun_fourier_transform_DFT_method5_full_complex(N,tab2);
    fun_fourier_transform_FFT_radix_4_N_4(N,tab3);

    cout<<"frequency Hz DFT:"<<endl;
    for(int j=0;j<N;j++)
    {
    cout.precision(4);
    cout<<round(tab2[j].real()*1000)/1000<<"  ";
    }

    cout<<endl;
    cout<<endl;
    for(int j=0;j<N;j++)
    {
    cout.precision(4);
    cout<<round(tab2[j].imag()*1000)/1000<<"  ";
    }
    cout<<endl;
    cout<<endl;

    cout<<"frequency Hz radix4:"<<endl;
    for(int j=0;j<N;j++)
    {
    cout.precision(4);
    cout<<round(tab3[j].real()*1000)/1000<<"  ";
    }

    cout<<endl;
    cout<<endl;
    for(int j=0;j<N;j++)
    {
    cout.precision(4);
    cout<<round(tab3[j].imag()*1000)/1000<<"  ";
    }
    cout<<endl;
    cout<<endl;

        if(((fabs(tab3[0].real())-fabs(tab2[0].real())>=-0.03)&&(fabs(tab3[0].real())-fabs(tab2[0].real())<=0.03))&&
           ((fabs(tab3[1].real())-fabs(tab2[1].real())>=-0.03)&&(fabs(tab3[1].real())-fabs(tab2[1].real())<=0.03))&&
           ((fabs(tab3[2].real())-fabs(tab2[2].real())>=-0.03)&&(fabs(tab3[2].real())-fabs(tab2[2].real())<=0.03))&&
           ((fabs(tab3[3].real())-fabs(tab2[3].real())>=-0.03)&&(fabs(tab3[3].real())-fabs(tab2[3].real())<=0.03)))
        {
            cout<<"DFT==FFT =>";
        for(int j=0;j<N;j++)
        {
          if(((tab3[j].real()-tab2[j].real()>=-0.03)&&(tab3[j].real()-tab2[j].real()<=0.03)))
          {

            cout.precision(4);
            cout<<round(tab2[j].real()*1000)/1000<<"  ";//system("pause");
          }
            else {
                cout<<-1<<" . ";
            }
        }cout<<", b1="<<b1<<" b2="<<b2<<" b3="<<b3<<endl;system("pause");
        //    plik<<a1<<" "<<a2<<" "<<a3<<" "<<a4<<" "<<a5<<" "<<a11<<" , "<<a12<<" "<<a13<<" "<<a14<<" "<<a15<<" "<<a16<<" "<<endl;
       }
   }}}
    //cout<<"end:"<<endl;
    cout<<endl;
    cout<<endl;
    //plik.close();
    system("pause");
    return 0;
}
///////////////
void fun_fourier_transform_DFT_method5_full_complex(int N,std::complex<double> tab[])
{
    const double pi=3.141592653589793238462;
    std::complex<double> tab2[16]={};    // tab2[]==N
    std::complex<double>  w[1]={{1,1}};


double zmienna1=2*pi/(float)N;
for (int i=0;i<N;i++)
{
    for(int j=0;j<N;j++)
    {
          //complex number method:
          w[0].real()=-cos(i*j*zmienna1+0.11);
          w[0].imag()=(-sin(i*j*zmienna1+0.11));
          tab2[i]=tab2[i]+tab[j]*w[0];

    }
}

    for(int j=0;j<N;j++)
    {
      tab[j].real() =tab2[j].real()*2/N;
      tab[j].imag() =tab2[j].imag()*2/N;
    }

}
//////////////////
void fun_inverse_bits_radix_4(int N,std::complex<double> tab[])
{

}
///////////////////
void fun_fourier_transform_FFT_radix_4_N_4(int N,std::complex<double> tab[])
{
    const double pi=3.141592653589793238462;
    std::complex<double> tab2[64]={};    // tab2[]==N

    std::complex<double>  w0[1]={{1,0}};
    std::complex<double>  w1[1]={{1,0}};
    std::complex<double>  w2[1]={{1,0}};
    std::complex<double>  w3[1]={{1,0}};
    std::complex<double>  a0,a1,a2,a3,a4,a6,a9;

    double zm=2*pi/4;
    double wbm=2*pi/N;
    double fi;
    int nr1=1;
    int nr2=1;
    int nr3=1;

        if(b1==0){nr1=-1;}
        else if(b1==1){nr1=1;}
        else{}
        if(b2==0){nr2=-1;}
        else if(b2==1){nr2=1;}
        else{}
        if(b3==0){nr3=-1;}
        else if(b3==1){nr3=1;}
        else{}
        //cout<<"b1="<<b1<<endl<<endl;

    //nr1=1;
    //nr2=1;
    //nr3=1;

    fi=0.11;

          a0.real()=nr1*cos(0*zm+fi);
          a0.imag()=-sin(0*zm+fi);
          a1.real()=nr1*cos(1*zm+fi);
          a1.imag()=-sin(1*zm+fi);
          a2.real()=nr1*cos(2*zm+fi);
          a2.imag()=-sin(2*zm+fi);
          a3.real()=nr1*cos(3*zm+fi);
          a3.imag()=-sin(3*zm+fi);
          a4.real()=nr1*cos(4*zm+fi);
          a4.imag()=-sin(4*zm+fi);
          a6.real()=nr1*cos(6*zm+fi);
          a6.imag()=-sin(6*zm+fi);
          a9.real()=nr1*cos(9*zm+fi);
          a9.imag()=-sin(9*zm+fi);

        //cout.precision(3);
        //cout<<" ["<<round(a0.real()*1000)/1000<<" "<<round(a0.imag()*1000)/1000<<"i] ["<<round(a0.real()*1000)/1000<<" "<<round(a0.imag()*1000)/1000<<"i] ["<<round(a0.real()*1000)/1000<<" "<<round(a0.imag()*1000)/1000<<"i] ["<<round(a0.real()*1000)/1000<<" "<<round(a0.imag()*1000)/1000<<"i] "<<endl;
       //// cout<<" ["<<round(a0.real()*1000)/1000<<" "<<round(a0.imag()*1000)/1000<<"i] ["<<round(a1.real()*1000)/1000<<" "<<round(a1.imag()*1000)/1000<<"i] ["<<round(a2.real()*1000)/1000<<" "<<round(a2.imag()*1000)/1000<<"i] ["<<round(a3.real()*1000)/1000<<" "<<round(a3.imag()*1000)/1000<<"i] "<<endl;
       // cout<<" ["<<round(a0.real()*1000)/1000<<" "<<round(a0.imag()*1000)/1000<<"i] ["<<round(a2.real()*1000)/1000<<" "<<round(a2.imag()*1000)/1000<<"i] ["<<round(a4.real()*1000)/1000<<" "<<round(a4.imag()*1000)/1000<<"i] ["<<round(a6.real()*1000)/1000<<" "<<round(a6.imag()*1000)/1000<<"i] "<<endl;
        //cout<<" ["<<round(a0.real()*1000)/1000<<" "<<round(a0.imag()*1000)/1000<<"i] ["<<round(a3.real())<<" "<<round(a3.imag())<<"i] ["<<round(a6.real())<<" "<<round(a6.imag())<<"i] ["<<round(a9.real())<<" "<<round(a9.imag())<<"i] "<<endl;
       //system("pause");

    //radix-4

          w0[0].real()=nr3*cos(0+fi);
          w0[0].imag()=-sin(0+fi);

          w2[0].real()=nr2*cos(0*0*2*pi/(N/4)+fi);
          w2[0].imag()=-sin(0*0*2*pi/(N/4)+fi);

          tab2[0]=(-a0*tab[0]-a0*tab[1]-a0*tab[2]-a0*tab[3])*w0[0]*w2[0];

          w1[0].real()=nr3*cos(0*wbm+fi);
          w1[0].imag()=-sin(0*wbm+fi);

          tab2[1]=(-a0*tab[0]-a1*tab[1]-a2*tab[2]-a3*tab[3])*w1[0]*w2[0];

          w1[0].real()=nr3*cos(2*0*wbm+fi);
          w1[0].imag()=-sin(2*0*wbm+fi);
          tab2[2]=(-a0*tab[0]-a2*tab[1]-a4*tab[2]-a6*tab[3])*w1[0]*w2[0];

          w1[0].real()=nr3*cos(3*0*wbm+fi);
          w1[0].imag()=-sin(3*0*wbm+fi);

          tab2[3]=(-a0*tab[0]-a3*tab[1]-a6*tab[2]-a9*tab[3])*w1[0]*w2[0];


    for(int j=0;j<N;j++)
    {
      tab[j].real() =tab2[j].real()*2/N;
      tab[j].imag() =tab2[j].imag()*2/N;
    }

}