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"content": "<p>You are given a <strong>0-indexed</strong> <code>m x n</code> binary matrix <code>matrix</code> and an integer <code>numSelect</code>, which denotes the number of <strong>distinct</strong> columns you must select from <code>matrix</code>.</p>\n\n<p>Let us consider <code>s = {c<sub>1</sub>, c<sub>2</sub>, ...., c<sub>numSelect</sub>}</code> as the set of columns selected by you. A row <code>row</code> is <strong>covered</strong> by <code>s</code> if:</p>\n\n<ul>\n\t<li>For each cell <code>matrix[row][col]</code> (<code>0 <= col <= n - 1</code>) where <code>matrix[row][col] == 1</code>, <code>col</code> is present in <code>s</code> or,</li>\n\t<li><strong>No cell</strong> in <code>row</code> has a value of <code>1</code>.</li>\n</ul>\n\n<p>You need to choose <code>numSelect</code> columns such that the number of rows that are covered is <strong>maximized</strong>.</p>\n\n<p>Return <em>the <strong>maximum</strong> number of rows that can be <strong>covered</strong> by a set of </em><code>numSelect</code><em> columns.</em></p>\n\n<p> </p>\n<p><strong>Example 1:</strong></p>\n<img alt=\"\" src=\"https://assets.leetcode.com/uploads/2022/07/14/rowscovered.png\" style=\"width: 240px; height: 400px;\" />\n<pre>\n<strong>Input:</strong> matrix = [[0,0,0],[1,0,1],[0,1,1],[0,0,1]], numSelect = 2\n<strong>Output:</strong> 3\n<strong>Explanation:</strong> One possible way to cover 3 rows is shown in the diagram above.\nWe choose s = {0, 2}.\n- Row 0 is covered because it has no occurrences of 1.\n- Row 1 is covered because the columns with value 1, i.e. 0 and 2 are present in s.\n- Row 2 is not covered because matrix[2][1] == 1 but 1 is not present in s.\n- Row 3 is covered because matrix[2][2] == 1 and 2 is present in s.\nThus, we can cover three rows.\nNote that s = {1, 2} will also cover 3 rows, but it can be shown that no more than three rows can be covered.\n</pre>\n\n<p><strong>Example 2:</strong></p>\n<img alt=\"\" src=\"https://assets.leetcode.com/uploads/2022/07/14/rowscovered2.png\" style=\"height: 250px; width: 84px;\" />\n<pre>\n<strong>Input:</strong> matrix = [[1],[0]], numSelect = 1\n<strong>Output:</strong> 2\n<strong>Explanation:</strong> Selecting the only column will result in both rows being covered since the entire matrix is selected.\nTherefore, we return 2.\n</pre>\n\n<p> </p>\n<p><strong>Constraints:</strong></p>\n\n<ul>\n\t<li><code>m == matrix.length</code></li>\n\t<li><code>n == matrix[i].length</code></li>\n\t<li><code>1 <= m, n <= 12</code></li>\n\t<li><code>matrix[i][j]</code> is either <code>0</code> or <code>1</code>.</li>\n\t<li><code>1 <= numSelect <= n</code></li>\n</ul>\n",
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"Iterate through all possible sets of exactly <code>cols</code> columns.",
"For each valid set, check how many rows are covered, and return the maximum."
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