#!/usr/bin/env python
# coding: utf-8

# This notebook was prepared by [Donne Martin](https://github.com/donnemartin). Source and license info is on [GitHub](https://github.com/donnemartin/interactive-coding-challenges).

# # Challenge Notebook

# ## Problem: Flip one bit from 0 to 1 to maximize the longest sequence of 1s.
# 
# * [Constraints](#Constraints)
# * [Test Cases](#Test-Cases)
# * [Algorithm](#Algorithm)
# * [Code](#Code)
# * [Unit Test](#Unit-Test)
# * [Solution Notebook](#Solution-Notebook)

# ## Constraints
# 
# * Is the input an int, base 2?
#     * Yes
# * Can we assume the input is a 32 bit number?
#     * Yes
# * Do we have to validate the length of the input?
#     * No
# * Is the output an int?
#     * Yes
# * Can we assume the inputs are valid?
#     * No
# * Can we assume we are using a positive number since Python doesn't have an >>> operator?
#     * Yes
# * Can we assume this fits memory?
#     * Yes

# ## Test Cases
# 
# * None -> Exception
# * All 1's -> Count of 1s
# * All 0's -> 1
# * General case
#     * 0000 1111 1101 1101 1111 0011 1111 0000 -> 10 (ten)

# ## 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 flip_bit(self, num):
        # TODO: Implement me
        pass


# ## Unit Test

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

# In[ ]:


# %load test_flip_bit.py
import unittest


class TestBits(unittest.TestCase):

    def test_flip_bit(self):
        bits = Bits()
        self.assertRaises(TypeError, bits.flip_bit, None)
        self.assertEqual(bits.flip_bit(0), 1)
        self.assertEqual(bits.flip_bit(-1), bits.MAX_BITS)
        num = int('00001111110111011110001111110000', base=2)
        expected = 10
        self.assertEqual(bits.flip_bit(num), expected)
        num = int('00000100111011101111100011111011', base=2)
        expected = 9
        self.assertEqual(bits.flip_bit(num), expected)
        num = int('00010011101110111110001111101111', base=2)
        expected = 10
        self.assertEqual(bits.flip_bit(num), expected)
        print('Success: test_print_binary')


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


if __name__ == '__main__':
    main()


# ## Solution Notebook
# 
# Review the [Solution Notebook]() for a discussion on algorithms and code solutions.