zoj 2531 Traveller

#include <iostream>using namespace std;int DecimaltoGray ( int x ){    return x ^ ( x >> 1 );}int GraytoDecimal ( int x ){    int y = x;    while ( x >>= 1 ) y ^= x;    return y;}int main(){    int n, m;    while ( 1 )    {        cin >> n >> m;        if ( n == 0 ) break;        for ( int i = 0; i < n - 1; i++ ) cout << DecimaltoGray ( (i+m) % n ) << ' ';        cout << DecimaltoGray ( (n-1+m) % n ) << endl;    }    return 0;}