892. Surface Area of 3D Shapes

[Tcdian]

892. Surface Area of 3D Shapes

在 N * N 的网格上，我们放置一些 1 * 1 * 1  的立方体。

每个值 v = grid[i][j] 表示 v 个正方体叠放在对应单元格 (i, j) 上。

请你返回最终形体的表面积。

Example 1

Input: [[2]]
Output: 10

Example 2

Input: [[1,2],[3,4]]
Output: 34

Example 3

Input: [[1,0],[0,2]]
Output: 16

Example 4

Input: [[1,1,1],[1,0,1],[1,1,1]]
Output: 32

Example 5

Input: [[2,2,2],[2,1,2],[2,2,2]]
Output: 46

Note

• 1 <= N <= 50
• 0 <= grid[i][j] <= 50

[Tcdian]

Solution

• JavaScript Solution

/**
 * @param {number[][]} grid
 * @return {number}
 */
var surfaceArea = function(grid) {
    let result = 0;
    let direction = [-1, 0, 1, 0, -1];
    
    for (let i = 0 ; i < grid.length; i++) {
        for (let j = 0; j < grid[0].length; j++) {
            if (grid[i][j] !== 0) {
                result += grid[i][j] * 1 * 4 + 1 * 1 * 2;
                for (let d = 0; d < 4; d++) {
                    let directionX = i + direction[d];
                    let directionY = j + direction[d + 1];
                    if (directionX >= 0
                       && directionX < grid.length
                       && directionY >= 0
                       && directionY < grid.length
                    ) {
                        result -= Math.min(grid[i][j], grid[directionX][directionY]);
                    }
                }   
            }
        }
    }
    
    return result;
};