堆的遍历，构造一个完全二叉树，遍历堆。

def travel(x, deep, res):
    if deep == 6:
        print("".join(res))
        return res[:-1]
    res.append(x[2*deep+1])
    res = travel(x, deep+1, res)
    res.append(x[2*deep+2])
    res = travel(x, deep+1, res)
    return res[:-1]


if __name__ == '__main__':
    a = ["0", "1"] * 63
    a = ["0"] + a
    travel(a, 0, [])