883.projection area of 3d shapes

Description

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.

题目链接：https://leetcode.com/problems/projection-area-of-3d-shapes/description/

Difficulty: easy

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.

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

分析

updating

参考代码

class Solution:
def projectionArea(self, grid):
    row=len(grid)
    col=len(grid[0])
    index=0
    for i in range(row):
        index+=max(grid[i])
    for j in range(col):
        ii=0
        for i in range(row):
            if(grid[i][j]!=0):
                index+=1
            ii=max(ii,grid[i][j])
        index+=ii
    return index