883. Projection Area of 3D Shapes

Posted bernieloveslife

tags:

篇首语:本文由小常识网(cha138.com)小编为大家整理,主要介绍了883. Projection Area of 3D Shapes相关的知识,希望对你有一定的参考价值。

On a N * N grid, we place some 1 * 1 * 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 grid cell (i, j).

Now 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.

Here, 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: [[2]]
Output: 5

Example 2:

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

技术分享图片

Example 3:

Input: [[1,0],[0,2]]
Output: 8

Example 4:

Input: [[1,1,1],[1,0,1],[1,1,1]]
Output: 14

Example 5:

Input: [[2,2,2],[2,1,2],[2,2,2]]
Output: 21

Note:

  • 1 <= grid.length = grid[0].length <= 50
  • 0 <= grid[i][j] <= 50
class Solution:
    def projectionArea(self, grid):
        """
        :type grid: List[List[int]]
        :rtype: int
        """
        front = [0] * len(grid)
        side = [0] * len(grid)
        top = 0
        for i in range(len(grid)):
            for j in range(len(grid[i])):
                if grid[i][j] == 0:
                    continue
                top += 1
                front[i] = max(front[i],grid[i][j])
                side[j] = max(side[j],grid[i][j])
        return top + sum(front) + sum(side)







以上是关于883. Projection Area of 3D Shapes的主要内容,如果未能解决你的问题,请参考以下文章

[LeetCode] 883. Projection Area of 3D Shapes 三维物体的投影面积

[LeetCode&Python] Problem 883. Projection Area of 3D Shapes

LeetCode 883 Projection Area of 3D Shapes 解题报告

Capabilities of the SELECT Statement(SELECT语句的功能):Projection(投影)Selection(选择)Joining(连接)

Area of Mushroom HDU - 4946

Numerical Testing Reportes of A New Conjugate Gradient Projection Method for Convex Constrained Nonl