Solution

All Implemented Interfaces:
```
public final class Solution

                    
```
319 - Bulb Switcher.
Medium
There are n bulbs that are initially off. You first turn on all the bulbs, then you turn off every second bulb.
On the third round, you toggle every third bulb (turning on if it's off or turning off if it's on). For the <code>i<sup>th</sup></code> round, you toggle every i bulb. For the <code>n<sup>th</sup></code> round, you only toggle the last bulb.
Return the number of bulbs that are on after n rounds.
Example 1:
Input: n = 3
Output: 1
Explanation: At first, the three bulbs are off, off, off. After the first round, the three bulbs are on, on, on. After the second round, the three bulbs are on, off, on. After the third round, the three bulbs are on, off, off. So you should return 1 because there is only one bulb is on.
Example 2:
Input: n = 0
Output: 0
Example 3:
Input: n = 1
Output: 1
Constraints:
- <code>0 <= n <= 10<sup>9</sup></code>

Nested Class Summary

Nested Classes
Modifier and Type	Class	Description

Field Summary

Fields
Modifier and Type	Field	Description

Constructor Summary

Constructors
Constructor	Description
`Solution()`

Enum Constant Summary

Enum Constants
Enum Constant	Description

Method Summary

Modifier and Type	Method	Description
`final Integer`	`bulbSwitch(Integer n)`

Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail
- Solution
```
Solution()
```

Method Detail
- bulbSwitch
```
 final Integer bulbSwitch(Integer n)
```