Values That Are Row Minima and Column Maxima

### Problem In the matrix of distinct values, return all entries that are the minimum of their row and the maximum of their column. The source allows any output order. With globally distinct entries there can in fact be at most one such value. ```cpp class Solution { public: vector<int> luckyNumbers(vector<vector<int>>& matrix); }; ``` ### Examples **Example 1:** ```text Input: matrix = [[2,5],[7,9]] Output: [7] Explanation:7 is the second row's minimum and the first column's maximum. ``` **Example 2:** ```text Input: matrix = [[1,4],[3,2]] Output: [] Explanation: The row minima1 and2 are both below another value in their respective columns. ``` ### Constraints - The rectangular matrix has 1 to 50 rows and 1 to 50 columns. - Values are integers in `[1,100000]` and globally distinct. - Apply both the row-minimum and column-maximum tests to each candidate. ### Contract considerations All matrix values are distinct. Return every value passing both tests; the result may be empty. ```hint Read the boundary condition Check both required directions of comparison for each returned value. The distinct-value premise and the possibility of an empty result still apply. ``` ### Boundary reminders All matrix values are distinct. Return every value passing both tests; the result may be empty.