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"title": "Find All Groups of Farmland",
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"content": "<p>You are given a <strong>0-indexed</strong> <code>m x n</code> binary matrix <code>land</code> where a <code>0</code> represents a hectare of forested land and a <code>1</code> represents a hectare of farmland.</p>\n\n<p>To keep the land organized, there are designated rectangular areas of hectares that consist <strong>entirely</strong> of farmland. These rectangular areas are called <strong>groups</strong>. No two groups are adjacent, meaning farmland in one group is <strong>not</strong> four-directionally adjacent to another farmland in a different group.</p>\n\n<p><code>land</code> can be represented by a coordinate system where the top left corner of <code>land</code> is <code>(0, 0)</code> and the bottom right corner of <code>land</code> is <code>(m-1, n-1)</code>. Find the coordinates of the top left and bottom right corner of each <strong>group</strong> of farmland. A <strong>group</strong> of farmland with a top left corner at <code>(r<sub>1</sub>, c<sub>1</sub>)</code> and a bottom right corner at <code>(r<sub>2</sub>, c<sub>2</sub>)</code> is represented by the 4-length array <code>[r<sub>1</sub>, c<sub>1</sub>, r<sub>2</sub>, c<sub>2</sub>].</code></p>\n\n<p>Return <em>a 2D array containing the 4-length arrays described above for each <strong>group</strong> of farmland in </em><code>land</code><em>. If there are no groups of farmland, return an empty array. You may return the answer in <strong>any order</strong></em>.</p>\n\n<p> </p>\n<p><strong>Example 1:</strong></p>\n<img alt=\"\" src=\"https://assets.leetcode.com/uploads/2021/07/27/screenshot-2021-07-27-at-12-23-15-copy-of-diagram-drawio-diagrams-net.png\" style=\"width: 300px; height: 300px;\" />\n<pre>\n<strong>Input:</strong> land = [[1,0,0],[0,1,1],[0,1,1]]\n<strong>Output:</strong> [[0,0,0,0],[1,1,2,2]]\n<strong>Explanation:</strong>\nThe first group has a top left corner at land[0][0] and a bottom right corner at land[0][0].\nThe second group has a top left corner at land[1][1] and a bottom right corner at land[2][2].\n</pre>\n\n<p><strong>Example 2:</strong></p>\n<img alt=\"\" src=\"https://assets.leetcode.com/uploads/2021/07/27/screenshot-2021-07-27-at-12-30-26-copy-of-diagram-drawio-diagrams-net.png\" style=\"width: 200px; height: 200px;\" />\n<pre>\n<strong>Input:</strong> land = [[1,1],[1,1]]\n<strong>Output:</strong> [[0,0,1,1]]\n<strong>Explanation:</strong>\nThe first group has a top left corner at land[0][0] and a bottom right corner at land[1][1].\n</pre>\n\n<p><strong>Example 3:</strong></p>\n<img alt=\"\" src=\"https://assets.leetcode.com/uploads/2021/07/27/screenshot-2021-07-27-at-12-32-24-copy-of-diagram-drawio-diagrams-net.png\" style=\"width: 100px; height: 100px;\" />\n<pre>\n<strong>Input:</strong> land = [[0]]\n<strong>Output:</strong> []\n<strong>Explanation:</strong>\nThere are no groups of farmland.\n</pre>\n\n<p> </p>\n<p><strong>Constraints:</strong></p>\n\n<ul>\n\t<li><code>m == land.length</code></li>\n\t<li><code>n == land[i].length</code></li>\n\t<li><code>1 <= m, n <= 300</code></li>\n\t<li><code>land</code> consists of only <code>0</code>'s and <code>1</code>'s.</li>\n\t<li>Groups of farmland are <strong>rectangular</strong> in shape.</li>\n</ul>\n",
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"code": "class Solution {\npublic:\n vector<vector<int>> findFarmland(vector<vector<int>>& land) {\n \n }\n};",
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"code": "class Solution(object):\n def findFarmland(self, land):\n \"\"\"\n :type land: List[List[int]]\n :rtype: List[List[int]]\n \"\"\"\n ",
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"code": "\n\n/**\n * Return an array of arrays of size *returnSize.\n * The sizes of the arrays are returned as *returnColumnSizes array.\n * Note: Both returned array and *columnSizes array must be malloced, assume caller calls free().\n */\nint** findFarmland(int** land, int landSize, int* landColSize, int* returnSize, int** returnColumnSizes){\n\n}",
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"code": "impl Solution {\n pub fn find_farmland(land: Vec<Vec<i32>>) -> Vec<Vec<i32>> {\n \n }\n}",
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"code": "(define/contract (find-farmland land)\n (-> (listof (listof exact-integer?)) (listof (listof exact-integer?)))\n\n )",
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"Since every group of farmland is rectangular, the top left corner of each group will have the smallest x-coordinate and y-coordinate of any farmland in the group.",
"Similarly, the bootm right corner of each group will have the largest x-coordinate and y-coordinate of any farmland in the group.",
"Use DFS to traverse through different groups of farmlands and keep track of the smallest and largest x-coordinate and y-coordinates you have seen in each group."
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