java.lang.Object
g2301_2400.s2397_maximum_rows_covered_by_columns.Solution

public class Solution extends Object
2397 - Maximum Rows Covered by Columns.<p>Medium</p> <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> <p>Let us consider <code>s = {c<sub>1</sub>, c<sub>2</sub>, &hellip;., 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> <ul> <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> <li><strong>No cell</strong> in <code>row</code> has a value of <code>1</code>.</li> </ul> <p>You need to choose <code>numSelect</code> columns such that the number of rows that are covered is <strong>maximized</strong>.</p> <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> <p><strong>Example 1:</strong></p> <p><img src="https://assets.leetcode.com/uploads/2022/07/14/rowscovered.png" alt="" /></p> <p><strong>Input:</strong> matrix = [[0,0,0],[1,0,1],[0,1,1],[0,0,1]], numSelect = 2</p> <p><strong>Output:</strong> 3</p> <p><strong>Explanation:</strong> One possible way to cover 3 rows is shown in the diagram above.</p> <p>We choose s = {0, 2}.</p> <ul> <li> <p>Row 0 is covered because it has no occurrences of 1.</p> </li> <li> <p>Row 1 is covered because the columns with value 1, i.e. 0 and 2 are present in s.</p> </li> <li> <p>Row 2 is not covered because matrix[2][1] == 1 but 1 is not present in s.</p> </li> <li> <p>Row 3 is covered because matrix[2][2] == 1 and 2 is present in s.</p> </li> </ul> <p>Thus, we can cover three rows.</p> <p>Note that s = {1, 2} will also cover 3 rows, but it can be shown that no more than three rows can be covered.</p> <p><strong>Example 2:</strong></p> <p><img src="https://assets.leetcode.com/uploads/2022/07/14/rowscovered2.png" alt="" /></p> <p><strong>Input:</strong> matrix = [[1],[0]], numSelect = 1</p> <p><strong>Output:</strong> 2</p> <p><strong>Explanation:</strong> Selecting the only column will result in both rows being covered since the entire matrix is selected.</p> <p>Therefore, we return 2.</p> <p><strong>Constraints:</strong></p> <ul> <li><code>m == matrix.length</code></li> <li><code>n == matrix[i].length</code></li> <li><code>1 <= m, n <= 12</code></li> <li><code>matrix[i][j]</code> is either <code>0</code> or <code>1</code>.</li> <li><code>1 <= numSelect <= n</code></li> </ul>
  • Constructor Details

    • Solution

      public Solution()
  • Method Details

    • maximumRows

      public int maximumRows(int[][] matrix, int numSelect)