C++ Math Crisis! :x

[bloodyhell]

Hey everyone, umm I got a problem with this C++ program I'm writing.
The objective of the program is to ask the user which level he wants (1 or 2) and give him math problems accordingly... the problems are randomly selected and the sentences like Good job, bravo! , or try again etc... are randmoly selected as well. I wrote the whole program and I'm pretty sure I wrote it correctly but when compiling its giving me several errors like Lvalue Required etc...

if anybody could compile the program and fix it or show me how to fix it I'd be very grateful...

NOTE: I know the program can be done a lot easier through several methods but unfortunately our programming professor wants it this way, no arrays no pointers no linked lists and no strings :/

here is the code :

#include <iostream.h>
#include <conio.h>
#include <stdlib.h>
#include <math.h>


int A,B,gcd,flag,level,answer;
int a,b,c,d,e,f,g;
int x,y,N,M,bla,bli,result;


void hmulti(int, int);

void hdivision(int, int);

int hGCD(int, int);

int hcorrect();

int hwrong();






main(){

 int k,num,denom;


do{
  k = 0;
  cout << "Hello there! Welcome" << endl;

  cout << "\n";

  cout << "Please input your level: ";
  cin >> level;
   if(level < 0 || level > 2){
    cout << "Thank you and goodbye!";
    getch();
    return 0;
   }

  if(level == 1){
    do{
     flag = 0;
      g = rand()%2;

       switch(g){
        case 1:
         hmulti(e,f);
         break;

        case 2:
         hdivision(e,f);
         break;
       }

      cout << "Try another question? 1 (for yes) or 2 (for no) :";
      cin >> flag;

    }while(flag == 1);

    if (flag == 0)
     cout << "Thank You, and good bye!" << endl;

  }

  else if(level == 2){
   do{
    flag = 0;
     randomize();
     a=rand()%12 +1;
     b=rand()%12 +1;
     c=rand()%12 +1;
     d=rand()%12 +1;

     randomize();
     int random =rand()%3;

     gcd =(int) hGCD(b,d);

     A = (gcd*a)/b;
     B = (gcd*c)/d;

       switch(random){
        case 1:
         result = a +b;
         break;
        case 2:
         result = a - b;
         break;
        case 3:
         A = a*c;
         B = b*d;
         break;
        case 4:
         A = a*d;
         B = b*c;
         break;
       }

     if(random == 1){

      cout << "What is the value of " << a << "/" << b << " + " << c << "/" << d << " in its simplest form ? ";
      cin >> num >> denom;

       if(num == result && denom == gcd)
        hcorrect();
       else
        hwrong();
     }

     else if (random == 2){

		cout << "What is the value of " << a << "/" << b << " - " << c << "/" << d << " in its simplest form ? ";
      cin >> num >> denom;

       if(num == result && denom == gcd)
        hcorrect();
       else
        hwrong();
     }

     else if(random == 3){


    	cout << "What is the value of " << a << "/" << b << " * " << c << "/" << d << " in its simplest form ? ";
      cin >> num >> denom;

       if(num == result && denom == gcd)
        hcorrect();
       else
        hwrong();
     }

     else if(random == 4){

      cout << "What is the value of" << a << "/" << b << " / " << c << "/" << d << " in its simplest form ?";
      cin >> num >> denom;

       if(num == result && denom == gcd)
        hcorrect();
       else
        hwrong();
     }
  }while( flag ==1);

  if (flag == 0)
   cout << "Thank you, and goodbye!" << endl;

 }while(k = 0);

 getch();
 return 0;
}


/************************************************************************/


void hmulti(int a,int b){

  int answer,c,d,hi;

	 randomize();
    a = rand()%9;
    b = rand()%9;

     cout << "How much is " << a << " times " << b << "?" ;
     cin >> answer;

     if(answer == a*b)
      hcorrect();

     else
	   hwrong();
}

/************************************************************************/

void hdivision(int d,int n){
  int answer,remainder,a,b;

    randomize();
    d=rand()%9;
    n=rand()%100;

     cout << "How many times does " << d << " go into " << n << "?" ;
     cin >> answer >> remainder;

      if(answer == n/d)
       hcorrect();

      else if(answer != n/d)
	    hwrong();

}

/************************************************************************/

int hGCD(int N, int D){

  int z = N % D;
  while(z != 0){

    N = D;
    D = z;
    z = N % D;
  }
  return D;
}



/************************************************************************/


hcorrect(){

  randomize();
  c =1 + rand()%4;
 switch(c){
  case 1:
   cout << "Very Nice!" << endl;
   break;

  case 2:
   cout << "Nice work! " << endl;
   break;

  case 3:
   cout << "Keep up the good work" << endl;
   break;

  case 4:
   cout << "Excellent!" << endl;
   break;
  }
}

hwrong(){

  randomize();
  c =1 + rand()%4;

 switch(c){
  case 1:
   cout << "No.Please try again" << endl;
   break;

  case 2:
   cout << "Wrong, try once more" << endl;
   break;

  case 3:
   cout << "Not quiet, Keep trying!" << endl;
   break;
 }
}

[kempofighter]

I'll give you a few but you'll have to figure out the rest. First you main doesn't haev a return value. That is an error with my compiler (vc++ express 2008). hwrong and hcorrect also don't have return values.

My compiler couldn't even find <iostream.h>. You need to be using <iostream> instead. Also, specify std::cout rather than just cout. Also use <cstdlib> instead of <stdlib.h>. If you have been studying this website you'd know that those other headers are old and deprecated.

Honestly, there are really a lot of basic errors with this program. I'm not going to type out the whole laundry list. I think you should be able to figure out many of them simply by going to the line number of the error and studying what you wrote.

[Mythios]

Considering the way you've layed out your code. Under #include <math.h> you may as well use:
using namespace std;
That will make it so you don't have to use - std:: before cout, cin, endl etc

[bloodyhell]

hwrong and hcorrect have couts in them how do I return values when I'm making cout "sentences" :x