#include <iostream>
#include <cmath>
using namespace std;

double g(double x) {
   // f(x) = x*x
   return 1.-x * x ;
}


double bisekcija(double a, double b,double epsilon) {

  // funkcija naj bo kar f(x)=x^2

  double dx,f,fmid,xmid,rtb;
  int JMAX=100;
  f=g(a);
  fmid=g(b);
  if (f * fmid >= 0. ) { cout << "Ni vmesne nicle!" << endl ; return -1000; } 
  rtb= f < 0. ? (dx=b-a,a) : (dx=a-b,b);
  //cout << "rtb=" << rtb << " dx=" << dx << endl;
  for (int j=1;j<=JMAX;j++) {
    fmid=g(xmid=rtb+(dx*=0.5));
    if (fmid <= 0.) rtb = xmid;
    if (abs(dx) < epsilon || fmid == 0. ) { 
      cout << "korakov=" << j << endl;
      return rtb; 
    }
  }
  cout << "Ni vmesne nicle!" << endl ; 
  return -1000;
}  

int main() {


	double epsilon=1e-3;
	double a=0.1;
	double b=1000.2;

	double val= bisekcija(a,b,epsilon);
	cout << "bisekcija=" << val << endl;
	printf("natancno = %30.20f\n",val);

}