66 lines
1.7 KiB
Python
66 lines
1.7 KiB
Python
def _bst_new_node(name, phone):
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return {'name': name, 'phone': phone, 'left': None, 'right': None}
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def bst_insert(root, name, phone):
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if root is None:
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return _bst_new_node(name, phone)
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if name == root['name']:
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root['phone'] = phone
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elif name < root['name']:
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root['left'] = bst_insert(root['left'], name, phone)
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else:
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root['right'] = bst_insert(root['right'], name, phone)
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return root
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def bst_find(root, name):
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if root is None:
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return None
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if name == root['name']:
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return root['phone']
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elif name < root['name']:
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return bst_find(root['left'], name)
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else:
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return bst_find(root['right'], name)
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def _bst_min_node(root):
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node = root
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while node['left'] is not None:
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node = node['left']
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return node
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def bst_delete(root, name):
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if root is None:
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return None
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if name < root['name']:
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root['left'] = bst_delete(root['left'], name)
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elif name > root['name']:
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root['right'] = bst_delete(root['right'], name)
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else:
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# node found — three cases
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if root['left'] is None:
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return root['right']
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if root['right'] is None:
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return root['left']
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# two children: replace node with in-order successor
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successor = _bst_min_node(root['right'])
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root['name'] = successor['name']
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root['phone'] = successor['phone']
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root['right'] = bst_delete(root['right'], successor['name'])
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return root
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def bst_list_all(root):
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if root is None:
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return []
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return bst_list_all(root['left']) + [(root['name'], root['phone'])] + bst_list_all(root['right'])
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