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    "Normally, the factorial of a positive integer `n` is the product of all\n",
    "positive integers less than or equal to `n`.  For example, `factorial(10) = 10\n",
    "* 9 * 8 * 7 * 6 * 5 * 4 * 3 * 2 * 1`.\n",
    "\n",
    "We instead make a _clumsy factorial:_  using the integers in decreasing order,\n",
    "we swap out the multiply operations for a fixed rotation of operations:\n",
    "multiply (*), divide (/), add (+) and subtract (-) in this order.\n",
    "\n",
    "For example, `clumsy(10) = 10 * 9 / 8 + 7 - 6 * 5 / 4 + 3 - 2 * 1`.  However,\n",
    "these operations are still applied using the usual order of operations of\n",
    "arithmetic: we do all multiplication and division steps before any addition or\n",
    "subtraction steps, and multiplication and division steps are processed left to\n",
    "right.\n",
    "\n",
    "Additionally, the division that we use is _floor division_  such that `10 * 9\n",
    "/ 8` equals `11`.  This guarantees the result is an integer.\n",
    "\n",
    "`Implement the clumsy` function as defined above: given an integer `N`, it\n",
    "returns the clumsy factorial of `N`.\n",
    "\n",
    "\n",
    "\n",
    "**Example 1:**\n",
    "\n",
    "\n",
    "\n",
    "    Input: 4\n",
    "    Output:  7\n",
    "    Explanation: 7 = 4 * 3 / 2 + 1\n",
    "\n",
    "\n",
    "**Example 2:**\n",
    "\n",
    "\n",
    "\n",
    "    Input: 10\n",
    "    Output: 12\n",
    "    Explanation: 12 = 10 * 9 / 8 + 7 - 6 * 5 / 4 + 3 - 2 * 1\n",
    "\n",
    "\n",
    "\n",
    "\n",
    "**Note:**\n",
    "\n",
    "  1. `1 <= N <= 10000`\n",
    "  2. `-2^31 <= answer <= 2^31 - 1`  (The answer is guaranteed to fit within a 32-bit integer.)"
   ],
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    {
     "output_type": "execute_result",
     "data": {
      "text/plain": "clumsy (generic function with 1 method)"
     },
     "metadata": {},
     "execution_count": 1
    }
   ],
   "cell_type": "code",
   "source": [
    "# @lc code=start\n",
    "using LeetCode\n",
    "\n",
    "function clumsy(N::Int)\n",
    "    if N <= 4\n",
    "        return [1, 2, 6, 7][N]\n",
    "    end\n",
    "    mod = 1 + (N & 3)\n",
    "    return N + [1, 2, 2, -1][mod]\n",
    "end\n",
    "# @lc code=end"
   ],
   "metadata": {},
   "execution_count": 1
  },
  {
   "cell_type": "markdown",
   "source": [
    "---\n",
    "\n",
    "*This notebook was generated using [Literate.jl](https://github.com/fredrikekre/Literate.jl).*"
   ],
   "metadata": {}
  }
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