diff --git a/deepmind/balanced-binary-tree.py b/deepmind/part_one/balanced-binary-tree.py similarity index 100% rename from deepmind/balanced-binary-tree.py rename to deepmind/part_one/balanced-binary-tree.py diff --git a/deepmind/dijkstra.py b/deepmind/part_one/dijkstra.py similarity index 100% rename from deepmind/dijkstra.py rename to deepmind/part_one/dijkstra.py diff --git a/deepmind/efficiency.org b/deepmind/part_one/efficiency.org similarity index 100% rename from deepmind/efficiency.org rename to deepmind/part_one/efficiency.org diff --git a/deepmind/find-rotation-point.py b/deepmind/part_one/find-rotation-point.py similarity index 100% rename from deepmind/find-rotation-point.py rename to deepmind/part_one/find-rotation-point.py diff --git a/deepmind/inflight-entertainment.py b/deepmind/part_one/inflight-entertainment.py similarity index 100% rename from deepmind/inflight-entertainment.py rename to deepmind/part_one/inflight-entertainment.py diff --git a/deepmind/kth-to-last.py b/deepmind/part_one/kth-to-last.py similarity index 100% rename from deepmind/kth-to-last.py rename to deepmind/part_one/kth-to-last.py diff --git a/deepmind/merging-ranges.py b/deepmind/part_one/merging-ranges.py similarity index 100% rename from deepmind/merging-ranges.py rename to deepmind/part_one/merging-ranges.py diff --git a/deepmind/recursive-string-permutations.py b/deepmind/part_one/recursive-string-permutations.py similarity index 100% rename from deepmind/recursive-string-permutations.py rename to deepmind/part_one/recursive-string-permutations.py diff --git a/deepmind/reverse-linked-list.py b/deepmind/part_one/reverse-linked-list.py similarity index 100% rename from deepmind/reverse-linked-list.py rename to deepmind/part_one/reverse-linked-list.py diff --git a/deepmind/stock-price.py b/deepmind/part_one/stock-price.py similarity index 100% rename from deepmind/stock-price.py rename to deepmind/part_one/stock-price.py diff --git a/deepmind/which-appears-twice.py b/deepmind/part_one/which-appears-twice.py similarity index 100% rename from deepmind/which-appears-twice.py rename to deepmind/part_one/which-appears-twice.py diff --git a/deepmind/part_two/delete-node.py b/deepmind/part_two/delete-node.py new file mode 100644 index 000000000..4ed02ec30 --- /dev/null +++ b/deepmind/part_two/delete-node.py @@ -0,0 +1,57 @@ +import unittest + + +def delete_node(node): + if node.next: + node.value = node.next.value + node.next = node.next.next + else: + raise Exception( + "We cannot delete the last node in a linked list using this function" + ) + + +# Tests +class Test(unittest.TestCase): + class LinkedListNode(object): + def __init__(self, value, next=None): + self.value = value + self.next = next + + def get_values(self): + node = self + values = [] + while node is not None: + values.append(node.value) + node = node.next + return values + + def setUp(self): + self.fourth = Test.LinkedListNode(4) + self.third = Test.LinkedListNode(3, self.fourth) + self.second = Test.LinkedListNode(2, self.third) + self.first = Test.LinkedListNode(1, self.second) + + def test_node_at_beginning(self): + delete_node(self.first) + actual = self.first.get_values() + expected = [2, 3, 4] + self.assertEqual(actual, expected) + + def test_node_in_middle(self): + delete_node(self.second) + actual = self.first.get_values() + expected = [1, 3, 4] + self.assertEqual(actual, expected) + + def test_node_at_end(self): + with self.assertRaises(Exception): + delete_node(self.fourth) + + def test_one_node_in_list(self): + unique = Test.LinkedListNode(1) + with self.assertRaises(Exception): + delete_node(unique) + + +unittest.main(verbosity=2)