#include <stdio.h>
#include <math.h>

double MyFunc(double x)
{
    return sin(x);
}
/*MyFunc .............*/

double Pr(double Xleft, double Xright, int k)
/* метод прямоугольника*/
 {
     int i;
     double S,dx;
     dx = (Xright-Xleft)/k;
     S = 0;
     for(i = 0;i < k;i++)
     {
         S = S + dx*MyFunc(Xleft);
         Xleft = Xleft + dx;
         Xright = Xleft + dx;
     }
     return(S);
 }


double Tr(double Xleft, double Xright,int k)
/*метод трапеций*/
{
    int i;
    double S, dx;
    dx = (Xright-Xleft)/k;
    S = (MyFunc(Xleft) + MyFunc(Xright))/2;
    for(i = 1;i < k;i++)
    {
        Xleft = Xleft + dx;
        S = S + MyFunc(Xleft);
    }
    S = S*dx;
    return(S);
}


double Sim( double Xleft, double Xright, int k)
/*метод симпсона*/
{
    int i;
    double S,dx;
    dx = (Xright- Xleft)/k;
    S = MyFunc(Xleft) + MyFunc(Xright);
    for(i = 1;i < k;i++)
    {
        if (i%2==0)
        {
            Xleft = Xleft + dx;
            S = S + 2*MyFunc(Xleft);
        }
        else
        {
            Xleft = Xleft + dx;
            S = S+ 4*MyFunc(Xleft);
        }
    }
    S = S*dx/3;
    return(S);
}

int main()
{
    double a, b, Eps, s1, s2, s3, s4, s5, s6;
    int i, Ncycles1, Ncycles2, Ncycles3;

    a = 0.;
    b = M_PI/2;

    printf("Eps\t Xpr\t\t Prm\t Xtr\t\t Trm\t Xsim\t\t Simm\n");

    Eps = 0.1;
    for(i = 0;i < 4; i++)
    {
        Ncycles1 = 4;
        s1 = 0;
        s2 = Pr(a, b, Ncycles1);
        while(fabs(s1-s2)>Eps)
        {
            Ncycles1 = Ncycles1*2;
            s1 = s2;
            s2 = Pr(a, b, Ncycles1);
        }

        Ncycles2 = 4;
        s3 = 0;
        s4 = Tr(a, b, Ncycles2);
        while(fabs(s3-s4)>Eps)
        {
            Ncycles2 = Ncycles2*2;
            s3 = s4;
            s4 = Tr(a, b, Ncycles2);
        }

        Ncycles3 = 4;
        s5 = 0;
        s6 = Sim(a, b, Ncycles3);
        while(fabs(s5-s6)>Eps)
        {
            Ncycles3 = Ncycles3*2;
            s5 = s6;
            s6 = Sim(a, b, Ncycles3);
        }

        printf("%6.4f\t %8.5f\t\t %4d\t %8.5f\t\t %4d\t %8.5f\t\t %4d\n",Eps, s2, Ncycles1, s4, Ncycles2, s6, Ncycles3);
        Eps = Eps*0.1;
    }

    return 0;
}