7

#include<windows.h>
#include <iostream.h>
#include <iomanip.h>
#include <math.h>
#include <stdio.h>
#include <stdlib.h>

double F1(double x, double y1, double y2)
{
    return (y1*exp(x))/y2*x;
}

double F2(double x, double y1, double y2)
{
    return 2*y1+y2-4*x;
}

double out(double x, double u1, double Y1, double  u2, double Y2)
{
    printf("%5.4f\t%4.3f\t%4.3f\t%5.4f\t%4.3f\t%4.3f\t%5.4f\n",x,u1,Y1,fabs(u1-Y1),u2,Y2,fabs(u2-Y2));
    return 0;
}

void main(void)
{
    int a=1;
    int b=4;
    int ny=2;
    double u1[1000], u2[1000];
    double h, x;
    double Y1, Y2;
    int nx, np, k;

    cout<<"Vvedite kol-vo shagov setki nx: "<<endl;
    cin>>nx;
    cout<<"Vvedite shag vivoda dannich np: "<<endl;
    cin>>np;

    h=double(b-a)/nx;
    cout<<nx;
    u1[1]=2;
    u2[1]=exp(1);
    k=0;
    x=a;

    while (k<=nx)
    {
        k++;
        Y1 = u1[k]+(h/2)*F1(x, u1[k], u2[k]);
        Y2 = u2[k]+(h/2)*F2(x, u1[k], u2[k]);
        u1[k+1] = F1(x+h/2, Y1, Y2)*h+u1[k];
        u2[k+1] = F2(x+h/2, Y1, Y2)*h+u2[k];
        u1[0]=2*x;
        u2[0]=exp(x);
        out(x, u1[k], u1[0], u2[k], u2[0]);
        x+=h;
    }
    cout<<"Iksov = "<<k<<endl;
    cout<<"Otrezkov = "<<nx<<endl;
    cout<<"Shag = "<<h<<endl;
}