/**
 * @param {number[][]} matrix
 * @return {number[]}
 */
var luckyNumbers = function (matrix) {
  let minCol = matrix.map(row=>Math.min(...row))
  let maxRow = matrix[0].map((item,index)=>Math.max(...matrix.map(row=>row[index])))
  return maxRow.filter(v=>minCol.includes(v))
};

class Solution(object):
    def luckyNumbers (self, matrix):
        """
        :type matrix: List[List[int]]
        :rtype: List[int]
        """
        r,c = len(matrix),len(matrix[0])
        rMin, cMax = [10**9] * r, [0] * c
        for i in range(c):
            for j in range(r):
                rMin[i] = min(rMin[i], matrix[i][j])
                cMax[j] = max(cMax[j], matrix[i][j])
        ans = list()
        for i in range(r):
            for j in range(c):
                if matrix[i][j] == rMin[i] and matrix[i][j] == cMax[j]:
                    ans.append(matrix[i][j])
        return ans