feat: add python solution to lc problem: No.0319 (doocs#1877)

Author: nrhitik

solution/0300-0399/0319.Bulb Switcher/README.md

@@ -63,6 +63,9 @@
 <!-- 这里可写当前语言的特殊实现逻辑 -->
 
 ```python
+class Solution:
+    def bulbSwitch(self, n: int) -> int:
+        return int(n ** (1 / 2))
 
 ```
 

solution/0300-0399/0319.Bulb Switcher/README_EN.md

@@ -50,6 +50,9 @@ So you should return 1 because there is only one bulb is on.</pre>
 ### **Python3**
 
 ```python
+class Solution:
+    def bulbSwitch(self, n: int) -> int:
+        return int(n ** (1 / 2))
 
 ```
 

solution/0300-0399/0319.Bulb Switcher/Solution.py

@@ -0,0 +1,3 @@
+class Solution:
+    def bulbSwitch(self, n: int) -> int:
+        return int(n ** (1 / 2))