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

# Challenge Notebook¶

## Constraints¶

• Can we assume the inputs are valid?
• No
• Can we assume this fits memory?
• Yes

## Test Cases¶

• None as a number input -> Exception
• Negative index -> Exception

### get_bit¶

number   = 0b10001110, index = 3
expected = True


### set_bit¶

number   = 0b10001110, index = 4
expected = 0b10011110


### clear_bit¶

number   = 0b10001110, index = 3
expected = 0b10000110


### clear_bits_msb_to_index¶

number   = 0b10001110, index = 3
expected = 0b00000110


### clear_bits_index_to_lsb¶

number   = 0b10001110, index = 3
expected = 0b10000000


### update_bit¶

number   = 0b10001110, index = 3, value = 1
expected = 0b10001110
number   = 0b10001110, index = 3, value = 0
expected = 0b10000110
number   = 0b10001110, index = 0, value = 1
expected = 0b10001111

## 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 Bit(object):

def __init__(self, number):
# TODO: Implement me
pass

def get_bit(self, index):
# TODO: Implement me
pass

def set_bit(self, index):
# TODO: Implement me
pass

def clear_bit(self, index):
# TODO: Implement me
pass

def clear_bits_msb_to_index(self, index):
# TODO: Implement me
pass

def clear_bits_index_to_lsb(self, index):
# TODO: Implement me
pass

def update_bit(self, index, value):
# TODO: Implement me
pass


## Unit Test¶

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

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

class TestBit(unittest.TestCase):

def test_bit(self):
number = int('10001110', base=2)
bit = Bit(number)
self.assertEqual(bit.get_bit(index=3), True)
expected = int('10011110', base=2)
self.assertEqual(bit.set_bit(index=4), expected)
bit = Bit(number)
expected = int('10000110', base=2)
self.assertEqual(bit.clear_bit(index=3), expected)
bit = Bit(number)
expected = int('00000110', base=2)
self.assertEqual(bit.clear_bits_msb_to_index(index=3), expected)
bit = Bit(number)
expected = int('10000000', base=2)
self.assertEqual(bit.clear_bits_index_to_lsb(index=3), expected)
bit = Bit(number)
self.assertEqual(bit.update_bit(index=3, value=1), number)
bit = Bit(number)
expected = int('10000110', base=2)
self.assertEqual(bit.update_bit(index=3, value=0), expected)
bit = Bit(number)
expected = int('10001111', base=2)
self.assertEqual(bit.update_bit(index=0, value=1), expected)
print('Success: test_bit')

def main():
test = TestBit()
test.test_bit()

if __name__ == '__main__':
main()


## Solution Notebook¶

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