Problem URL: Max increase to keep city skyline

For grid[i][j], it can't be higher than the maximun of its row nor the maximum of its column. So the maximum increasing height for a building at (i, j) is min(row[i], col[j]) - grid[i][j].

rows: maximum for every row, cols: maximum for every col, the fisrt loop of grid calcule maximum for every row and every col. The second loop calculate the maximum increasing height for every building.

class Solution:
    def maxIncreaseKeepingSkyline(self, grid: List[List[int]]) -> int:
        rows, cols = list(map(max, grid)), list(map(max, zip(*grid)))
        return sum(min(i, j) for i in rows for j in cols) - sum(map(sum, grid))

Time complexity: O(n^2)
Space complexity: O(n)