mirror of
https://github.com/IRBorisov/ConceptPortal.git
synced 2025-06-26 13:00:39 +03:00
74 lines
2.7 KiB
Python
74 lines
2.7 KiB
Python
''' Utility: Graph implementation. '''
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from typing import Dict, Iterable, Optional, cast
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class Graph:
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''' Directed graph. '''
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def __init__(self, graph: Optional[Dict[str, list[str]]]=None):
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if graph is None:
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self._graph = cast(Dict[str, list[str]], dict())
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else:
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self._graph = graph
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def contains(self, node_id: str) -> bool:
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''' Check if node is in graph. '''
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return node_id in self._graph
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def has_edge(self, id_from: str, id_to: str) -> bool:
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''' Check if edge is in graph. '''
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return self.contains(id_from) and id_to in self._graph[id_from]
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def add_node(self, node_id: str):
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''' Add node to graph. '''
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if not self.contains(node_id):
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self._graph[node_id] = []
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def add_edge(self, id_from: str, id_to: str):
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''' Add edge to graph. '''
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self.add_node(id_from)
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self.add_node(id_to)
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if id_to not in self._graph[id_from]:
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self._graph[id_from].append(id_to)
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def expand_outputs(self, origin: Iterable[str]) -> list[str]:
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''' Expand origin nodes forward through graph edges. '''
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result: list[str] = []
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marked: set[str] = set(origin)
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for node_id in origin:
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if self.contains(node_id):
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for child_id in self._graph[node_id]:
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if child_id not in marked and child_id not in result:
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result.append(child_id)
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position: int = 0
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while position < len(result):
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node_id = result[position]
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position += 1
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if (node_id not in marked):
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marked.add(node_id)
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for child_id in self._graph[node_id]:
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if child_id not in marked and child_id not in result:
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result.append(child_id)
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return result
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def topological_order(self) -> list[str]:
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''' Return nodes in topological order. '''
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result: list[str] = []
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marked: set[str] = set()
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for node_id in self._graph.keys():
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if node_id not in marked:
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to_visit: list[str] = [node_id]
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while len(to_visit) > 0:
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node = to_visit[-1]
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if node in marked:
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if node not in result:
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result.append(node)
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to_visit.remove(node)
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else:
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marked.add(node)
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if len(self._graph[node]) > 0:
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for child_id in self._graph[node]:
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if child_id not in marked:
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to_visit.append(child_id)
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result.reverse()
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return result
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