grid, each value
grid[i][j]represents the height of a building located there. We are allowed to increase the height of any number of buildings, by any amount (the amounts can be different for different buildings). Height 0 is considered to be a building as well.
1 < grid.length = grid.length <= 50.
grid[i][j]are in the range
grid[i][j]occupy the entire grid cell: that is, they are a
1 x 1 x grid[i][j]rectangular prism.