Leetcode PHP题解--D65 892. Surface Area of 3D Shapes

<?php

class Solution {

​

    /**

     * @param Integer[][] $grid

     * @return Integer

     */

    function surfaceArea($grid) {

        $total = 0;

        $ys = count($grid);

        for($i = 0; $i<$ys; $i++){

            $xs = count($grid[$i]);

            for($j = 0; $j<$xs; $j++){

                $total += $grid[$i][$j]*4+2*($grid[$i][$j]!=0);

                if($i+1<$ys){

                    $total -= min($grid[$i][$j],$grid[$i+1][$j])*2;

                }

                if($j+1<$ys){

                    $total -= min($grid[$i][$j],$grid[$i][$j+1])*2;

                }

            }

        }

        return $total;

    }

}