Bit manipulation algorithm to check is_power_of_four

bit_manipulation/is_power_of_four.py

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+"""
+Author :- mehul-sweeti-agrawal
+
+Task :- Given an integer N, find whether that integer is a power of 4 or not.
+
+    Input  - N
+    Output - Yes/No
+
+"""
+
+def is_power_of_four(N: int) -> bool:
+  """
+    Returns whether a number is a power of 4 or not
+    >>> is_power_of_four(8)
+    False
+    >>> is_power_of_four(4)
+    True
+    >>> is_power_of_four(16)
+    True
+    >>> is_power_of_four(-1)
+    Traceback (most recent call last):
+        ...
+    ValueError: number must be positive
+    >>> is_power_of_four(9.8)
+    Traceback (most recent call last):
+        ...
+    TypeError: unsupported operand type(s) for &: 'float' and 'float'
+  """
+
+  #For non-positive numbers
+  if N <= 0:
+    raise ValueError("number must be positive")
+
+  #If number is a power of 2 and ends with 4 or 6
+  if (N & (N-1) == 0) and (N%10 == 6 or N%10 == 4):
+    return True
+  else:
+    return False
+
+
+if __name__ == "__main__":
+  import doctest
+
+  doctest.testmod()
+
+
+
+
+