#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include "f.h"
#define MAXIT 1234500

 double f(double x)
{
    return x*x;
}

double solve(double (*f)(double x), double a,double b, double eps,double*r)
{
    double h=b-a,Sn,S2n;
    int i,n=2,k;
    double sum1=0,sum2,fa=f(a),fb=f(b);
    sum2=f(a+h);
    Sn=0.5*h*(fa+fb);
    for(i=1;i<n;i++)
    {
        sum1+=f(a+(2*i)*h);
        sum2+=f(a+(2*i+1)*h);
    }
    Sn=(h/3)*(fa+2*sum1+4*sum2+fb);


    for (k=1; k<MAXIT;k++)
    {
        sum2=0;
        h/=2;
        for(i=0;i<n;i++)
    {
        sum2+=h*f(a+(2*i+1)*h);
    }

        S2n=1/2*Sn+sum2;
        n*=2;
        printf("S2n=%lf\n",S2n);
        if(fabs(S2n-Sn)<eps)
        {
         //   printf("N=%d\n",n);
            *r=S2n; return 1;
        }
        Sn=S2n;
    }
    if( k==MAXIT)
        return -1;
    return 0;

}