Package g0301_0400.s0319_bulb_switcher
Class Solution
java.lang.Object
g0301_0400.s0319_bulb_switcher.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
ith
round, you toggle every `i` bulb. For the nth
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:**
* 0 <= n <= 109
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Constructor Summary
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Method Summary
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Constructor Details
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Solution
public Solution()
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Method Details
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bulbSwitch
public int bulbSwitch(int n)
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