5c9079a410
Manually merging: - README.md: I added the description from universe/README.md into the heading of dotfiles/README.md. - .envrc: dotfiles/.envrc was a superset of universe/.envrc - .gitignore: Adding some of the ignored patterns from universe/.gitignore to dotfiles/.gitignore Everything else here should be a simple rename.
64 lines
1.7 KiB
Python
64 lines
1.7 KiB
Python
import unittest
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def kth_to_last_node(k, x):
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a, b = x, x
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if k == 0:
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raise Exception('Value of 0 for k is not supported')
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for _ in range(k - 1):
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if not a.next:
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raise Exception('Value of {} for k is too large'.format(k))
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a = a.next
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while a.next:
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a, b = a.next, b.next
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return b
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class Test(unittest.TestCase):
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class LinkedListNode(object):
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def __init__(self, value, next=None):
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self.value = value
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self.next = next
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def get_values(self):
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node = self
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values = []
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while node is not None:
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values.append(node.value)
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node = node.next
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return values
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def setUp(self):
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self.fourth = Test.LinkedListNode(4)
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self.third = Test.LinkedListNode(3, self.fourth)
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self.second = Test.LinkedListNode(2, self.third)
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self.first = Test.LinkedListNode(1, self.second)
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def test_first_to_last_node(self):
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actual = kth_to_last_node(1, self.first)
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expected = self.fourth
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self.assertEqual(actual, expected)
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def test_second_to_last_node(self):
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actual = kth_to_last_node(2, self.first)
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expected = self.third
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self.assertEqual(actual, expected)
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def test_first_node(self):
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actual = kth_to_last_node(4, self.first)
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expected = self.first
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self.assertEqual(actual, expected)
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def test_k_greater_than_linked_list_length(self):
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with self.assertRaises(Exception):
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kth_to_last_node(5, self.first)
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def test_k_is_zero(self):
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with self.assertRaises(Exception):
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kth_to_last_node(0, self.first)
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unittest.main(verbosity=2)
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