/*
 * Programmieren fuer Physiker, WS 2009/10
 *
 * Klausur, Aufg. 6
 */

#include <iostream>
using namespace std ;

// convert n to base 3, digits of number are
// returned in the array "digs", return value is the number of digits
// least-significant-digit is in index 0
int convert_base3( int digs[], int n) 
{
    int nrdigits = 0 ;
    do {
	digs[nrdigits] = n%3 ;
	nrdigits++ ;
	n /= 3 ;
    }
    while (n>0)  ;
    
    for (int i=nrdigits-1; i>=0; --i)
	cout << digs[i] ;
    cout << " in Basis drei" << endl ;

    return nrdigits ;
}

// check whether array "digs" is palindrom in range 0..(nrdigits-1)
bool test_palindrom( int digs[], int nrdigits)
{
    for (int i=0; i<nrdigits; ++i)  // checks everything twice, harmless
	if (digs[i] != digs[nrdigits-1-i])
	     return false ;
    return true ;
}
    
int main()
{
    long n ;
    int nrdigs ;
    int digs[50] ;
    
    cout << "Basis 3, Palindrom-Test" << endl ;
    cout << "Zahl bitte: " ;
    cin >> n ;

    nrdigs = convert_base3( digs, n) ;

    if (test_palindrom( digs, nrdigs))
	cout << "ist Palindrom" << endl ;
    else
	cout << "kein Palindrom" << endl ;
}