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
• For the output, do we set corresponding bits in screen?
• Yes
• Can we assume this fits memory?
• Yes

## Test Cases¶

• Invalid inputs -> Exception
• screen is empty
• width = 0
• any input param is None
• x1 or x2 is out of bounds
• General case for len(screen) = 20, width = 32:
• x1 = 2, x2 = 6
• screen = int('00111110', base=2)
• x1 = 68, x2 = 80
• screen, int('00001111', base=2)
• screen, int('11111111', base=2)
• screen, int('10000000', base=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 BitsScreen(object):

def draw_line(self, screen, width, x1, x2):
# TODO: Implement me
pass


## Unit Test¶

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

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

class TestBitsScreen(unittest.TestCase):

def test_draw_line(self):
bits_screen = BitsScreen()
screen = []
for _ in range(20):
screen.append(int('00000000', base=2))
bits_screen.draw_line(screen, width=32, x1=68, x2=80)
self.assertEqual(screen, int('00001111', base=2))
self.assertEqual(screen, int('11111111', base=2))
self.assertEqual(screen, int('10000000', base=2))
bits_screen.draw_line(screen, width=32, x1=2, x2=6)
self.assertEqual(screen, int('00111110', base=2))
bits_screen.draw_line(screen, width=32, x1=10, x2=13)
self.assertEqual(screen, int('00111100', base=2))
print('Success: test_draw_line')

def main():
test = TestBitsScreen()
test.test_draw_line()

if __name__ == '__main__':
main()


## Solution Notebook¶

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