#include <stdio.h>
#include <stdlib.h>
#include <time.h>
#include <math.h>
#include "f.h"

int main(void)
{
    double x,res,eps;
    clock_t time;

    printf("x and EPS ");
    if((scanf("%lf",&x)!=1) || scanf("%lf",&eps)!=1)
    {
        fprintf(stderr,"Can not read x or eps\n");
        return ERROR_READ;
    }
    if(eps<0 || x<0)
    {
        fprintf(stderr,"Incorrect EPS!\n");
        return ERROR_READ;
    }
    time = clock();
    res = fun(x,eps);
    printf("RESULT: %lf\nCalculation error: %lf\nTIME: %lf\n",res,fabs(res - log(x)),((double)(clock() - time))/CLOCKS_PER_SEC);

    return 0;
}
#include <math.h>
#include "f.h"

double fun(double x,double eps)
{
        int counter1 = 0,counter2 = 0,i;
        double res = 0,k = 1;


        while(x >= 1)
        {
                x /= 2;
                counter1 ++;
        }
        while(x <= 0.1)
        {
                x *= 2;
                counter2 ++;
        }

        x -= 1;
        for(i = 1;fabs(k/(1+x))>eps;i++)
        {
                k *= x;
                if(i%2 == 0)
                        res -= k/i;
                else
                        res += k/i;
        }


        res += (counter1*M_LN2 - counter2*M_LN2);

        return res;
}
#ifndef F_H
#define F_H

double fun(double x0, double eps);

#define ERROR_READ 1
#endif