```
public class Solution
extends Object
```
1739 - Building Boxes\. Hard You have a cubic storeroom where the width, length, and height of the room are all equal to `n` units. You are asked to place `n` boxes in this room where each box is a cube of unit side length. There are however some rules to placing the boxes: * You can place the boxes anywhere on the floor. * If box `x` is placed on top of the box `y`, then each side of the four vertical sides of the box `y` **must** either be adjacent to another box or to a wall. Given an integer `n`, return _the **minimum** possible number of boxes touching the floor._ **Example 1:** ![](https://assets.leetcode.com/uploads/2021/01/04/3-boxes.png) **Input:** n = 3 **Output:** 3 **Explanation:** The figure above is for the placement of the three boxes. These boxes are placed in the corner of the room, where the corner is on the left side. **Example 2:** ![](https://assets.leetcode.com/uploads/2021/01/04/4-boxes.png) **Input:** n = 4 **Output:** 3 **Explanation:** The figure above is for the placement of the four boxes. These boxes are placed in the corner of the room, where the corner is on the left side. **Example 3:** ![](https://assets.leetcode.com/uploads/2021/01/04/10-boxes.png) **Input:** n = 10 **Output:** 6 **Explanation:** The figure above is for the placement of the ten boxes. These boxes are placed in the corner of the room, where the corner is on the back side. **Constraints:** * 1 <= n <= 10⁹

Class Solution