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 boxy
, then each side of the four vertical sides of the boxy
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:
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:
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:
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