#include <stdio.h>
#include <math.h>
#include <stdlib.h>
#include "methods.h"

double delta = 0.0000001;

extern double F(double x){
    double result = 2*x*x - pow(x,4) - 1 - log(x) ;
    result = x+20.0/23.0*result;
    return result;
}

double ITER(double X0,double Eps,int &N)
{
    if (Eps<=0.0) {puts("Неверное задание точности \n");exit (1);}
    double X1=Round(F(X0), delta);
    double X2=F(X1);
    N = 2;
    while( (X1 - X2)*(X1 - X2) > fabs((2*X1-X0-X2)*Eps) )
    {
        X0 = X1;
        X1 = X2;
        X2 = F(X1);
        N++;
    }
    return X2;
}

double Round (double X,double Delta)

{

    if (Delta<=1E-9) {puts("Неверное задание точности округления \n");exit(1);}

    if (X>0.0) return (Delta*(long((X/Delta)+0.5)));

    else return (Delta*(long((X/Delta)-0.5)));

}


int main(){
    int N;
    double res;
        double eps = 0.1;
        for (int j = 0; j<7; j++){
            res = ITER(0.93, eps, N);
            printf("F(x) = 0 => x = %.7f\n", Round(res,eps));
            printf("N(EPS) = %u(%.7f)\n", N, eps);
            printf("D(x) = %.7f\n\n", Round(res,eps)-1.00000);
            eps /= 10;
        }
    return 0;
}