#include <cstdlib>
#include <iostream>
#include <graphics.h>
#include <math.h>

/*
 * Author: MyZone
 * Company: ZoneSofe Inc
 * Date: 23.02.11
 */

using namespace std;

char* toString(int number){
    char* temp = new char[256];
    return itoa(number,temp,10);
}

long double formula(long double x, int a,int b){
    double y0 = (5*x-9)/(7.5*a*b)+18;
    if(y0>=0){
        double y1 = 3*sqrt(y0);
        double y2 = -2*x+0.5/a ;
        double y3 = -exp(y2);

        return (y1 + y3)>300?301:(y1 + y3)<-300?-301:(y1 + y3);
    }else return formula(x+1,a,b);
    //return (x+15)*(x-5);
}

void drawCoord(long double scale){
    setcolor(8);

    line(0,300,960,300);
    line(480,0,480,600);

    for(int i=0;i<600;i+=5*scale){
        line(479,i,481,i);
        if(!(i%(50/(int)scale))){
            if(i-300) outtextxy(485,i,toString((300-i)/scale));
        }
    }
    for(int i=0;i<960;i+=5*scale){
        line(i,299,i,301);
        if(!(i%(50/(int)scale))){
            if(i-480) outtextxy(i,305,toString((i-480)/scale));
            }
    }
}
void draw(long double scale){
    clearviewport();
    drawCoord(scale);

    int a,b;
    a=10;
    b=100;

    setcolor(WHITE);

    moveto(-1,(int)formula(-481,a,b));

    for(int x=-480;x<480;x++){
        lineto(x+480,300-(int)formula(x/scale,a,b));
    }

    outtextxy(0,0,"1 :");
    outtextxy(20,0,toString(scale>1?scale:1));
}


int main(){
    long double scale = 1;
    initwindow(960,600);
    draw(scale);

    for(;;){
        char select = getch();
        if(select=='[' || select=='1'){
            if(scale<12) scale*=2;
        }else if(select==']' || select=='2'){
            if(scale>1) scale/=2;
        }
        draw(scale);
    }
}