Added solution for problem 342

quizzes/_342.py

@@ -0,0 +1,16 @@
+"""
+    Question: Power of Four
+    Desc:   Given an integer n, return True if it is a power of four. 
+            Otherwise, return False.
+            An integer n is a power of four if there exists an integer x 
+            such that n == 4^x.
+    URL: https://leetcode.com/problems/power-of-four/
+    Resource: Runtime: 28 ms, Memory Usage: 16.5 MB
+"""
+class Solution:
+    def isPowerOfFour(self, n: int) -> bool:
+        # A number is power of four if:
+        # 1. It's greater than 0
+        # 2. It's a power of two (n & (n-1)) == 0
+        # 3. The only set bit is at an even position
+        return n > 0 and (n & (n - 1)) == 0 and (n - 1) % 3 == 0