Dahl-Programming-Lab4-5

#include <iostream>
#include <cmath>
#include <math.h>

using namespace std;
int main(){
    cout << "Выберите способ: 1 - while, 2 - for, 3 - do while: ";
    int menu;
    cin >> menu;

    //Variables
    const float E = 2.71f;
    double a = 5.3;
    double t = 2;
    double deltat = 0.1, x;
    //

    switch (menu) {
    case 1:
        while (t<3)
        {
            x = a*pow(t,2) + pow(E,t);
            if (x<15)
            {
                double z = 6*pow(x,2)+2*x;
                cout<<"\tx = "<<x<<"\tz = "<<z<<endl;
                t += deltat;
            }
            else if (x>=15 && x<20)
            {
               double z = log(x);
               cout<<"\tx = "<<x<<"\tz = "<<z<<endl;
               t += deltat;
            }
            else {
                double z = 5 * pow(x,2);
                cout<<"\tx = "<<x<<"\tz = "<<z<<endl;
                t += deltat;
            }
        }
    break;

    case 2:
        for (double t2 = 2; t2<3; t2 += 0.1)
        {
            x = a*pow(t2,2) + pow(E,t2);
            if (x<15)
            {
                double z = 6*pow(x,2)+2*x;
                cout<<"\tx = "<<x<<"\tz = "<<z<<endl;
            }
            else if (x>=15 && x<20)
            {
               double z = log(x);
               cout<<"\tx = "<<x<<"\tz = "<<z<<endl;
            }
            else {
                double z = 5 * pow(x,2);
                cout<<"\tx = "<<x<<"\tz = "<<z<<endl;
            }
        }
    break;

    case 3:
        do
        {
            x = a*pow(t,2) + pow(E,t);
            if (x<15)
            {
                double z = 6*pow(x,2)+2*x;
                cout<<"\tx = "<<x<<"\tz = "<<z<<endl;
                t += deltat;
            }
            else if (x>=15 && x<20)
            {
               double z = log(x);
               cout<<"\tx = "<<x<<"\tz = "<<z<<endl;
               t += deltat;
            }
            else {
                double z = 5 * pow(x,2);
                cout<<"\tx = "<<x<<"\tz = "<<z<<endl;
                t += deltat;
            }
        } while (t<3);
    break;
    }

}