void grayCodes(char* number, int pos, int n, int reverse) {
if(pos == n) {
printf("%s\n", number);
return;
}
if (!reverse) {
number[pos] = '0';
grayCodes(number, pos+1, n, reverse);
number[pos] = '1';
grayCodes(number, pos+1, n, !reverse);
}
else{ //roles of 0,1 are reversed, so anti image of above!
number[pos] = '1';
grayCodes(number, pos+1, n, !reverse);
number[pos] = '0';
grayCodes(number, pos+1, n, reverse);
}
}
vector<int> grayCode(int n) {
int size = 1<<n;
vector<int> grayCodes(size);
for (int i=0; i<size; i++) {
int code = i ^ i>>1; // match calculation of gray code
grayCodes[i] = code;
}
return grayCodes;
}
