#include <iostream>
#include <math.h>
#include <conio.h>
using namespace std;
float a, b, e;
float f(float x){
        return pow(x, 2) + x - 2;
}
void dihot(){
        float c;
        c = (::a + ::b) / 2;
        cout << "\nc = " << c;
        while((fabs(::b - ::a) > ::e) && (f(c) != 0)){
                if (f(a) * f(c) < 0)
                        ::b = c;
                else
                        ::a = c;
                c = (::a + ::b) / 2;
                cout << "c = " << c <<endl;
        }
        cout << "\nx = " << c << endl;
}

void horda()
{
    while(fabs(::b - ::a) > ::e)
    {
        ::a = ::b - (::b - ::a) * f(::b)/(f(::b) - f(::a));
        ::b = ::a - (::a - ::b) * f(::a)/(f(::a) - f(::b));
    }
    cout << "x = " << ::b << endl;
}

int main(int argc, char* argv[])
{
        clrscr();
        while(true) {
                cout << "Start a = ";
                cin >> ::a;
                cout << "End b = ";
                cin >> ::b;
                if(f(::a) * f(::b) > 0)
                        cout << "ERROR! Try again!" << endl;
                else
                        break;
        }
        cout<<"e = ";
        cin >> ::e;
        cout << "--- METOD DIHOTOMII ---" << endl;
        dihot();
        cout << "-----------------------" << endl;
        cout << "------ METOD HORD ------" << endl;
        horda();
        cout << "------------------------" << endl;
        system("PAUSE");
        return 0;
}