This notebook was prepared by Donne Martin. Source and license info is on GitHub.

# Challenge Notebook¶

## Constraints¶

• Can we assume A and B are always ints?
• Yes
• Is the output an int?
• Yes
• Can we assume A and B are always the same number of bits?
• Yes
• Can we assume the inputs are valid (not None)?
• No
• Can we assume this fits memory?
• Yes

## Test Cases¶

• A or B is None -> Exception
• General case
  A = 11101
B = 01111
Result: 2

## Algorithm¶

Refer to the Solution Notebook. If you are stuck and need a hint, the solution notebook's algorithm discussion might be a good place to start.

## Code¶

In [ ]:
class Bits(object):

def bits_to_flip(self, a, b):
# TODO: Implement me
pass


## Unit Test¶

The following unit test is expected to fail until you solve the challenge.

In [ ]:
# %load test_bits_to_flip.py
import unittest

class TestBits(unittest.TestCase):

def test_bits_to_flip(self):
bits = Bits()
a = int('11101', base=2)
b = int('01111', base=2)
expected = 2
self.assertEqual(bits.bits_to_flip(a, b), expected)
print('Success: test_bits_to_flip')

def main():
test = TestBits()
test.test_bits_to_flip()

if __name__ == '__main__':
main()


## Solution Notebook¶

Review the Solution Notebook for a discussion on algorithms and code solutions.