Binario 1.0

#include <iostream.h>

int pot( int base, int exp ){
    int i, res=base;

    if( exp==0 ) return 1;
    if( exp>0 ) for( i=1 ; i<exp ; i++ ) res*=base;

    return res;
}

int de10_a2( int dec ){
    int bin=0, i;

    for( i=0 ; dec>1 ; i++ ){
        bin+=(dec%2)*pot(10,i);
        dec/=2;
    }

    bin+=pot(10,i);

    return bin;
}

int de2_a10( int bin ){
    int dec=0, i;

    for( i=0 ; bin>0 ; i++ ){
        dec+=(bin%10)*pot(2,i);
        bin=bin/10;
    }

    return dec;
}

int main(){
    int num, menu, retry;

    do{
        do{
            system("cls");
            cout << " \n 1. De decimal a binario \n 2. De binario a decimal \n 0. Salir \n ";
            cin >> menu;
        }while( menu<0 || menu>2 );

        system("cls");

        switch( menu ){
            case 0: return 0;
                      break;
            case 1:
                 cout << " \n Introduce el numero decimal: ";
                 cin >> num;
                 cout << " " << num << " en binario es " << de10_a2(num) << " ";
                      break;
            case 2:
                 cout << " \n Introduce el numero binario: ";
                 cin >> num;
                 cout << " " << num << " en decimal es " << de2_a10(num) << " ";
        }

        cout << " \n Volver al menu(1=si)? ";
        cin >> retry;
    }while( retry==1 );

    return 0;
}