019f8fd211
git-subtree-dir: users/wpcarro git-subtree-mainline:464bbcb15cgit-subtree-split:24f5a642afChange-Id: I6105b3762b79126b3488359c95978cadb3efa789
72 lines
1.6 KiB
Python
72 lines
1.6 KiB
Python
import unittest
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# Compute the fibonacci using a bottom-up algorithm.
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def fib(n):
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if n < 0:
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raise Error('Cannot call fibonacci with negative values')
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cache = [0, 1]
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for i in range(n):
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cache[0], cache[1] = cache[1], cache[0] + cache[1]
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return cache[0]
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# Compute the fibonacci using memoization.
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def fib_memoized(n):
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cache = {
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0: 0,
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1: 1,
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}
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def do_fib(n):
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if n < 0:
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raise Error('The fib function does not support negative inputs')
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if n in cache:
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return cache[n]
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cache[n - 1] = do_fib(n - 1)
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cache[n - 2] = do_fib(n - 2)
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return cache[n - 1] + cache[n - 2]
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return do_fib(n)
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# Tests
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class Test(unittest.TestCase):
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def test_zeroth_fibonacci(self):
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actual = fib(0)
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expected = 0
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self.assertEqual(actual, expected)
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def test_first_fibonacci(self):
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actual = fib(1)
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expected = 1
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self.assertEqual(actual, expected)
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def test_second_fibonacci(self):
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actual = fib(2)
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expected = 1
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self.assertEqual(actual, expected)
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def test_third_fibonacci(self):
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actual = fib(3)
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expected = 2
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self.assertEqual(actual, expected)
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def test_fifth_fibonacci(self):
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actual = fib(5)
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expected = 5
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self.assertEqual(actual, expected)
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def test_tenth_fibonacci(self):
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actual = fib(10)
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expected = 55
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self.assertEqual(actual, expected)
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def test_negative_fibonacci(self):
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with self.assertRaises(Exception):
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fib(-1)
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unittest.main(verbosity=2)
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