package gray_code;

import java.util.ArrayList;

public class GrayCode {

public class Solution {

public ArrayList<Integer> grayCode(int n) {

ArrayList<Integer> ans = new ArrayList<Integer>();

for (int i = 0; i < (1 << n); i++) {

ans.add(i ^ (i >> 1));

}

return ans;

}

}

public static class UnitTest {

}

}