0883. Projection Area of 3D Shapes

https://leetcode.com/problems/projection-area-of-3d-shapes

Description

You are given an n x n grid where we place some 1 x 1 x 1 cubes that are axis-aligned with the x, y, and z axes.

Each value v = grid[i][j] represents a tower of v cubes placed on top of the cell (i, j).

We view the projection of these cubes onto the xy, yz, and zx planes.

A projection is like a shadow, that maps our 3-dimensional figure to a 2-dimensional plane. We are viewing the "shadow" when looking at the cubes from the top, the front, and the side.

Return the total area of all three projections.

Example 1:

**Input:** grid = [[1,2],[3,4]]
**Output:** 17
**Explanation:** Here are the three projections ("shadows") of the shape made with each axis-aligned plane.

Example 2:

**Input:** grid = [[2]]
**Output:** 5

Example 3:

**Input:** grid = [[1,0],[0,2]]
**Output:** 8

Example 4:

**Input:** grid = [[1,1,1],[1,0,1],[1,1,1]]
**Output:** 14

Example 5:

**Input:** grid = [[2,2,2],[2,1,2],[2,2,2]]
**Output:** 21

Constraints:

• n == grid.length

• n == grid[i].length

• 1 <= n <= 50

• 0 <= grid[i][j] <= 50

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