From c08e1388e664e9f392d0a03835879c0efd49a403 Mon Sep 17 00:00:00 2001
From: siddwarr <siddharthwarrier2@gmail.com>
Date: Mon, 2 Oct 2023 21:28:17 +0530
Subject: [PATCH] added power_of_4

---
 bit_manipulation/power_of_4 | 61 +++++++++++++++++++++++++++++++++++++
 1 file changed, 61 insertions(+)
 create mode 100644 bit_manipulation/power_of_4

diff --git a/bit_manipulation/power_of_4 b/bit_manipulation/power_of_4
new file mode 100644
index 000000000..071a53a5d
--- /dev/null
+++ b/bit_manipulation/power_of_4
@@ -0,0 +1,61 @@
+"""
+
+Task:
+Given a positive int number. Return True if this number is power of 4
+or False otherwise.
+
+Implementation notes: Use bit manipulation.
+For example if the number is the power of 2 it's bits representation:
+n     = 0..100..00
+n - 1 = 0..011..11
+
+n & (n - 1) - no intersections = 0
+If the number is a power of 4 then it should be a power of 2 and the set bit should be at an odd position
+"""
+
+
+def power_of_4(number: int) -> bool:
+    """
+    Return True if this number is power of 4 or False otherwise.
+
+    >>> power_of_4(0)
+    False
+    >>> power_of_4(1)
+    True
+    >>> power_of_4(2)
+    False
+    >>> power_of_4(4)
+    True
+    >>> power_of_4(6)
+    False
+    >>> power_of_4(8)
+    False
+    >>> power_of_4(17)
+    False
+    >>> power_of_4(-1)
+    Traceback (most recent call last):
+        ...
+    ValueError: number must be positive
+    >>> power_of_4(1.2)
+    Traceback (most recent call last):
+        ...
+    TypeError: unsupported operand type(s) for &: 'float' and 'float'
+
+    """
+    if number <= 0:
+        raise ValueError("number must be positive")
+    if number & (number - 1) == 0:
+        c = 0
+        while number:
+            c+=1
+            number>>=1
+        if c&1==0:
+            return True
+        else:
+            return False
+
+
+if __name__ == "__main__":
+    import doctest
+
+    doctest.testmod()