New-Coder needing suggestions

Ok, Im not going to pretend to know I know that much C++ compared to most things I have read on this site. I am taking a highschool class in c++ and basically I thought it was way too simple and I actually want to learn something. OK, so I made this code for a base converter, and right now its working with bases 2-36. However, I'm pretty sure I must've wasted alot of time with some things. Anyone who wishes to can make suggestions on how to make it better. I've taken the class for about 5 weeks and am like a year ahead of the class so I hope this isn't that bad. If you think it sucks just say so, any constructive critisism helps. Thanks.

Code:

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#include<conio.h>                //Includes are from my Start.cpp
#include<iostream.h>
#include<iomanip.h>
#include<string.h>
#include<math.h>
#include<stdlib.h>
#include<stdio.h>
#include<dos.h>

#define MAX 20  //I Need a better way to do this


class Base    //First real time using classes, trying it out 
{
    public:
        long int real;
        char fake;
    private:
};

long int power(int x, int y); // Since I don't know an exponent function

void clear (int x, Base y []); // Clean-Up arrays

main()
{
    int base1;
    int base2;
    Base num1[MAX];
    Base num2[MAX];
    int y = MAX;
    int flag = 0;


    clrscr();
    clear (MAX, num1);
    clear (MAX, num2);

    cout << "\nEnter Number to be converted: " << endl << endl;


    for (int x=0;x<=MAX; x++)      // Asks for number in an array
    {

        if (x == MAX)
        {
            x--;
            break;
        }

        num1[x].real = getche();
        if (num1[x].real == 13)
        {
            num1[x].real = 0;
            x--;
            break;
        }

        else if ((num1[x].real >=48) && (num1[x].real <=57))
          num1[x].real -= 48;
        else if ((num1[x].real >=65) && (num1[x].real <=90))
          num1[x].real -= 55;

    }
    // Was there an easier way to do that?

    cout << endl << endl << "Enter base of that number: ";
    cin >> base1;
    cout << endl << "Enter base to be converted to: ";
    cin >> base2;

    int w = x;
    for (x; x >= 0; x-- )    // This loop does oldbase->base10->newbase
    {
        num2[0].real += num1[x].real * power(w-x, base1);
        for (y=0, num2[y].real; num2[y].real >= base2; y++)
        {
            num2[y+1].real += num2[y].real / base2;
            num2[y].real %= base2;

        }
    }

    cout << "\nYour new number is: ";

    if (base2 <= 10)
    {
        for (y=MAX;y>0;y--)
        {
            if ((flag == 0) && (num2[y-1].real != 0))
                flag = 1;

            if (flag==1)
                cout << num2[y-1].real;
        }

    }
    else if (base2 > 10)
    {
        for (y=MAX;y>0;y--)
            if (num2[y-1].real >= 10)
                num2[y-1].fake = 55 + num2[y-1].real;
        for (y=MAX;y>0;y--)
        {
            if ((flag == 0) && (num2[y-1].real != 0))
                flag = 1;

            if (flag==1)
            {
                if (num2[y-1].real < 10)
                    cout << num2[y-1].real;
                else if (num2[y-1].real >= 10)
                    cout << num2[y-1].fake;
            }
        }
    }

    getch();
    return 0;

}


void clear (int x, Base y [])
{
    for (x; x>=0; x--)
    {
        y[x].real = 0;
    }
}

long int power (int x , int y)
{
    if (x == 0)
        return 1;
    else
        return ( y * power(x-1, y));
}

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P.S i hope those tags worked =\

A couple of things I see:

>#define MAX 20 //I Need a better way to do this

const int MAX = 20;

Quote:

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void clear (int x, Base y [])
{
for (x; x>=0; x--)
{
y[x].real = 0;
}
}

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set the memory in Base's constructor: If you want a function like your clear() try memset()

Code:

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class Base    //First real time using classes, trying it out 
{
    public:
long int real;
char fake;
Base ();
    private:
};
Base::Base()
{
    real = 0;
}

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Also the data members would normally be private, and accessed through class member functions.

Quote:

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long int power (int x , int y)
{
if (x == 0)
return 1;
else
return ( y * power(x-1, y));
}

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There's a function called pow() in <cmath> formerly known as <math.h>

-Futura

other things to be addressed...use the new standard headers, i.e. <iostream> <cmath> <cstdlib>, etc. also, you should declare main like this...

int main()...I'm not sure if the way you have it will compile on newer compilers. old headers, like iostream.h, would produce warnings with newer compilers...newer compilers are more standard compliant.

Wow, Ok thanks. I'm going to go try to implement some of that stuff. BTW for the Const int MAX = 20; i know how to do that but i think a counter would be better. Also I'm having a problem with big numbers since like doing Z * 16 to the 10th power messes things up =\. I'll keep working on it, thanks again.

If you need more size you can use long double instead of long int, long double is 8 bytes (on my system) and long int is 4.

modulus % operator does not work with double, unless im mistaken (could be).

Quote:

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Originally posted by BakAttack
modulus % operator does not work with double, unless im mistaken (could be).

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The modulus "%" operator will work only with integral data types (char, int -- short, long, unsigned, signed)