Bulb Switcher Python Solution with Tests

lcpy gen -n 319   # by problem number
lcpy gen -s bulb_switcher   # by problem name

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.

Input: n = 0
Output: 0

Input: n = 1
Output: 1

from math import isqrt


class Solution:
    # Time: O(1)
    # Space: O(1)
    def bulb_switch(self, n: int) -> int:
        return isqrt(n)