leetcode説明--883.Projection Area of 3D Shapes

タイトル

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.

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

タイトルアドレス

説明する

この問題は実は簡単で,配列に対する横縦操作を考察することである.

Javaコード

class Solution {
    public int projectionArea(int[][] grid) {
        return countRow(grid)+countColumn(grid)+countPlan(grid);
    }
    
    private int countRow(int[][] grid){
        int result = 0;
        for(int i=0;i0){
                    result++;
                }
            }
        }
        return result;
    }
}