-
Notifications
You must be signed in to change notification settings - Fork 0
/
binary_tree.py
293 lines (235 loc) · 8.08 KB
/
binary_tree.py
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
import random
from unittest import TestCase
class TreeNode():
def __init__(self, value, parent=None, left=None, right=None):
self.value = value
self.parent = parent
self.left = left
self.right = right
@property
def level(self):
level = 1
parent = self.parent
while parent:
level += 1
parent = parent.parent
return level
def __repr__(self):
return "%s" % self.value
class BinaryTree():
def __init__(self):
self.__root = None
def extend(self, values):
map(self.add, values)
def add(self, value):
if not self.__root:
self.__root = TreeNode(value)
return
n = self.__root
while n:
if n.value < value:
if not n.right:
n.right = TreeNode(value, n)
return
n = n.right
else:
if not n.left:
n.left = TreeNode(value, n)
return
n = n.left
def delete(self, value):
self.__delete_node(self.__search_node_with(value))
def __delete_node(self, node):
if not node:
return
# No children case
if not node.left and not node.right:
self.__delete_node_with_no_children(node)
return
# One child case
if not node.left or not node.right:
self.__delete_node_with_one_child(node)
return
# Hardest case: two children
self.__delete_node_with_children(node)
def __delete_node_with_one_child(self, node):
child_node = node.left or node.right
parent = node.parent
child_node.parent = parent
if not parent:
self.__root = child_node
return
if parent.left == node:
parent.left = child_node
else:
parent.right = child_node
def __delete_node_with_no_children(self, node):
parent = node.parent
if not parent:
self.__root = None
return
if parent.left == node:
parent.left = None
else:
parent.right = None
def __delete_node_with_children(self, node):
predecessor = self.__max(node.left)
# Swap nodes (just the values :))
node.value, predecessor.value = predecessor.value, node.value
self.__delete_node(predecessor)
def min(self):
node = self.__min(self.__root)
return node and node.value
def __min(self, node=None):
n = node or self.__root
while n:
if not n.left:
return n
n = n.left
return None
def max(self):
node = self.__max(self.__root)
return node and node.value
def __max(self, node=None):
n = node or self.__root
while n:
if not n.right:
return n
n = n.right
return None
def predecessor(self, value):
node = self.__search_node_with(value)
if node and node.left:
return self.__max(node.left).value
return None
def sucessor(self, value):
node = self.__search_node_with(value)
if node and node.right:
return self.__min(node.right).value
return None
def __contains__(self, value):
return self.__search_node_with(value, self.__root) is not None
def __len__(self):
return len(list(self.__walk_dfs()))
def __walk_dfs(self, node=None):
node = node or self.__root
stack = []
current = node
while stack or current:
if current:
stack.append(current)
current = current.left
else:
n = stack.pop()
current = n.right
yield n
def __iter__(self):
return (n.value for n in self.__walk_dfs())
def __search_node_with(self, value, node=None):
n = node or self.__root
while n:
if n.value == value:
return n
n = n.left if n.value > value else n.right
return None
def __repr__(self):
repre = "\n".join(("%s%s" % (" " * node.level, node) for node in self.__walk_dfs()))
return "BinaryTree:\n%s" % repre
class BinaryTreeTestCase(TestCase):
def __assert_order(self, elements, expected_order):
tree = BinaryTree()
tree.extend(elements)
print tree
self.assertEquals(len(tree), len(elements))
self.assertEquals([item for item in tree], expected_order)
def test1(self):
self.__assert_order([5,3,8,9,10,11,0], [0,3,5,8,9,10,11])
def test2(self):
self.__assert_order([5,5,0,3,5,8,6,10], [0,3,5,5,5,6,8,10])
def test3(self):
self.__assert_order([], [])
def test4(self):
self.__assert_order([1], [1])
def test5(self):
self.__assert_order(range(1000)[::-1], range(1000))
def test6(self):
rand_elements = range(100000)
rand_elements = [rand_elements.pop(random.randrange(0, len(rand_elements))) for _ in range(len(rand_elements))]
self.__assert_order(rand_elements, range(100000))
def test7(self):
self.__assert_order([0,1,-1,-3,-5,9,-2], [-5,-3,-2,-1,0,1,9])
def test8(self):
self.__assert_order([6, 5, 1, 9, 2, 4, 3, 8, 7, 0], range(10))
def test9(self):
tree = BinaryTree()
tree.extend([5,5,0,3,5,8,6,10])
self.assertTrue(10 in tree)
self.assertEquals(tree.max(), 10)
def test10(self):
tree = BinaryTree()
tree.extend([5,5,0,3,5,8,6,10])
self.assertTrue(0 in tree)
self.assertEquals(tree.min(), 0)
def test11(self):
tree = BinaryTree()
tree.extend([5,5,0,3,5,8,6,10])
print tree
self.assertTrue(5 in tree)
self.assertEquals(tree.predecessor(5), 5)
self.assertTrue(6 in tree)
self.assertEquals(tree.predecessor(8), 6)
self.assertTrue(0 in tree)
self.assertEquals(tree.predecessor(0), None)
def test12(self):
tree = BinaryTree()
tree.extend([5,5,0,3,5,8,6,10])
self.assertTrue(3 in tree)
self.assertTrue(5 in tree)
self.assertEquals(tree.sucessor(3), 5)
self.assertTrue(8 in tree)
self.assertEquals(tree.sucessor(8), 10)
self.assertTrue(10 in tree)
self.assertEquals(tree.sucessor(10), None)
def test13(self):
tree = BinaryTree()
tree.extend([5,5,0,3,5,8,6,10])
self.assertTrue(3 in tree)
tree.delete(3)
self.assertFalse(3 in tree)
self.assertEquals([item for item in tree], [0,5,5,5,6,8,10])
self.assertTrue(5 in tree)
tree.delete(5)
self.assertTrue(5 in tree)
tree.delete(5)
tree.delete(5)
self.assertFalse(5 in tree)
self.assertEquals([item for item in tree], [0,6,8,10])
self.assertTrue(0 in tree)
tree.delete(0)
self.assertFalse(0 in tree)
self.assertEquals([item for item in tree], [6,8,10])
self.assertTrue(8 in tree)
tree.delete(8)
self.assertFalse(8 in tree)
self.assertEquals([item for item in tree], [6,10])
self.assertTrue(6 in tree)
tree.delete(6)
self.assertFalse(6 in tree)
self.assertEquals([item for item in tree], [10])
self.assertTrue(10 in tree)
tree.delete(10)
self.assertFalse(10 in tree)
self.assertEquals([item for item in tree], [])
self.assertEquals(len(tree), 0)
def test14(self):
tree = BinaryTree()
tree.add(1)
self.assertEquals(len(tree), 1)
self.assertTrue(1 in tree)
tree.delete(1)
self.assertFalse(1 in tree)
tree.add(2)
tree.add(3)
self.assertEquals(len(tree), 2)
def test15(self):
self.__assert_order(range(1000), range(1000))