forked from UNN/2026-rff_mp
88 lines
2.9 KiB
Python
88 lines
2.9 KiB
Python
"""
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Двоичное дерево поиска
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Узел — словарь:
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{'name': 'Имя', 'phone': '123', 'left': None, 'right': None}.
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"""
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def bst_insert(root: dict|None, name: str, phone: str) -> dict:
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"""Итеративно вставляет, возвращает новый корень (если корень меняется)."""
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if root == None:
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return {'name': name, 'phone': phone, 'left': None, 'right': None}
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# '674' < '722' == True, lol
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current = root
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while True:
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if current['name'] == name:
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current['phone'] = phone
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return root
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elif name < current['name']:
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if current['left'] == None:
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current['left'] = bst_insert(None, name, phone)
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return root
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else:
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current = current['left']
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else:
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if current['right'] == None:
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current['right'] = bst_insert(None, name, phone)
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return root
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else:
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current = current['right']
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# Увы, это самый лаконичный вариант, который я придумал.
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def bst_find(root: dict|None, name: str) -> str|None:
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"""Поиск в ширину."""
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node = find_node_to_delete(root, name)
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if node != None:
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return node['phone']
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def find_node_to_delete(root: dict|None, name: str) -> dict|None:
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"""Поиск в ширину."""
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while root != None:
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if root['name'] == name:
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return root
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elif name < root['name']:
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root = root['left']
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else:
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root = root['right']
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return None
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def find_minimal_child(root: dict) -> dict|None:
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while root['left']:
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root = root['left']
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return root
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def bst_delete(root: dict, name: str) -> None:
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"""Удаляет узел и возвращает новый корень."""
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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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# Случай 1: нет детей или один ребенок
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if root['left'] is None:
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return root['right']
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elif root['right'] is None:
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return root['left']
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# Случай 2: два ребенка
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min_node = find_minimal_child(root['right'])
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root['name'] = min_node['name']
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root['phone'] = min_node['phone']
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root['right'] = bst_delete(root['right'], min_node['name'])
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return root
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def bst_list_all(root: dict) -> list:
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"""Центрированный обход.
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Рекурсивно собирает записи в отсортированном порядке."""
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if root is None:
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return []
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node_values = {"name": root['name'], "phone": root['phone']}
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return bst_list_all(root['left']) + [node_values] + bst_list_all(root['right']) |