Surface Area of 3D Shapes
You are given an n x n grid where you have placed some 1 x 1 x 1 cubes. Each value v = grid[i][j] represents a tower of v cubes placed on top of cell (i, j).
After placing these cubes, you have decided to glue any directly adjacent cubes to each other, forming several irregular 3D shapes.
Return the total surface area of the resulting shapes.
Note: The bottom face of each shape counts toward its surface area.
Example 1
1 2 3 4
Input
grid = [[1,2],[3,4]]Output
34The total exposed surface area after gluing directly adjacent cubes is 34.
Example 2
1 1 1 1 0 1 1 1 1
Input
grid = [[1,1,1],[1,0,1],[1,1,1]]Output
32The empty center cell creates additional exposed faces, so the total surface area is 32.
Constraints
- n == grid.length == grid[i].length
- 1 <= n <= 50
- 0 <= grid[i][j] <= 50