dev/democards/problems/problems/73.set-matrix-zeroes.ipynb

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    "Given an ` _m_ x _n_` matrix. If an element is **0** , set its entire row and\n",
    "column to **0**. Do it [**in-place**](https://en.wikipedia.org/wiki/In-\n",
    "place_algorithm).\n",
    "\n",
    "**Follow up:**\n",
    "\n",
    "  * A straight forward solution using O( _m_ _n_ ) space is probably a bad idea.\n",
    "  * A simple improvement uses O( _m_ \\+ _n_ ) space, but still not the best solution.\n",
    "  * Could you devise a constant space solution?\n",
    "\n",
    "\n",
    "\n",
    "**Example 1:**\n",
    "\n",
    "![](https://assets.leetcode.com/uploads/2020/08/17/mat1.jpg)\n",
    "\n",
    "\n",
    "\n",
    "    Input: matrix = [[1,1,1],[1,0,1],[1,1,1]]\n",
    "    Output: [[1,0,1],[0,0,0],[1,0,1]]\n",
    "\n",
    "\n",
    "**Example 2:**\n",
    "\n",
    "![](https://assets.leetcode.com/uploads/2020/08/17/mat2.jpg)\n",
    "\n",
    "\n",
    "\n",
    "    Input: matrix = [[0,1,2,0],[3,4,5,2],[1,3,1,5]]\n",
    "    Output: [[0,0,0,0],[0,4,5,0],[0,3,1,0]]\n",
    "\n",
    "\n",
    "\n",
    "\n",
    "**Constraints:**\n",
    "\n",
    "  * `m == matrix.length`\n",
    "  * `n == matrix[0].length`\n",
    "  * `1 <= m, n <= 200`\n",
    "  * `-231 <= matrix[i][j] <= 231 - 1`"
   ],
   "metadata": {}
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   "outputs": [
    {
     "output_type": "execute_result",
     "data": {
      "text/plain": "set_zeroes (generic function with 1 method)"
     },
     "metadata": {},
     "execution_count": 1
    }
   ],
   "cell_type": "code",
   "source": [
    "# @lc code=start\n",
    "using LeetCode\n",
    "\n",
    "function set_zeroes(matrix::Vector{Vector{Int}})::Vector{Vector{Int}}\n",
    "    is_col = false\n",
    "    m, n = length(matrix), length(matrix[1])\n",
    "\n",
    "    for i = 1:m\n",
    "        matrix[i][1] == 0 && (is_col = true)\n",
    "\n",
    "        for j = 2:n\n",
    "            matrix[i][j] == 0 && (matrix[i][1] = matrix[1][j] = 0)\n",
    "        end\n",
    "    end\n",
    "\n",
    "    for i = 2:m, j = 2:n\n",
    "        (matrix[i][1] == 0 || matrix[1][j] == 0) && (matrix[i][j] = 0)\n",
    "    end\n",
    "\n",
    "    # See if the first row needs to be set to zero as well\n",
    "    if matrix[1][1] == 0\n",
    "        for j = 1:n\n",
    "            matrix[1][j] = 0\n",
    "        end\n",
    "    end\n",
    "\n",
    "    # See if the first column needs to be set to zero as well\n",
    "    if is_col\n",
    "        for i = 1:m\n",
    "            matrix[i][1] = 0\n",
    "        end\n",
    "    end\n",
    "\n",
    "    return matrix\n",
    "end\n",
    "# @lc code=end"
   ],
   "metadata": {},
   "execution_count": 1
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