結果

問題 No.1065 電柱 / Pole (Easy)
ユーザー Nagisa
提出日時 2020-05-29 22:13:47
言語 Python3
(3.13.1 + numpy 2.2.1 + scipy 1.14.1)
結果
TLE  
実行時間 -
コード長 3,470 bytes
コンパイル時間 332 ms
コンパイル使用メモリ 13,056 KB
実行使用メモリ 78,936 KB
最終ジャッジ日時 2024-11-06 05:10:24
合計ジャッジ時間 4,281 ms
ジャッジサーバーID
（参考情報） 		judge5 / judge1
このコードへのチャレンジ
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ファイルパターン 結果
sample AC * 2
other TLE * 1 -- * 45
権限があれば一括ダウンロードができます

ソースコード

diff # 

from math import sqrt
from collections import deque, namedtuple


# we'll use infinity as a default distance to nodes.
inf = float('inf')
Edge = namedtuple('Edge', 'start, end, cost')


def make_edge(start, end, cost=1):
  return Edge(start, end, cost)


class Graph:
    def __init__(self, edges):
        # let's check that the data is right
        wrong_edges = [i for i in edges if len(i) not in [2, 3]]
        if wrong_edges:
            raise ValueError('Wrong edges data: {}'.format(wrong_edges))

        self.edges = [make_edge(*edge) for edge in edges]

    @property
    def vertices(self):
        return set(
            sum(
                ([edge.start, edge.end] for edge in self.edges), []
            )
        )

    def get_node_pairs(self, n1, n2, both_ends=True):
        if both_ends:
            node_pairs = [[n1, n2], [n2, n1]]
        else:
            node_pairs = [[n1, n2]]
        return node_pairs

    def remove_edge(self, n1, n2, both_ends=True):
        node_pairs = self.get_node_pairs(n1, n2, both_ends)
        edges = self.edges[:]
        for edge in edges:
            if [edge.start, edge.end] in node_pairs:
                self.edges.remove(edge)

    def add_edge(self, n1, n2, cost=1, both_ends=True):
        node_pairs = self.get_node_pairs(n1, n2, both_ends)
        for edge in self.edges:
            if [edge.start, edge.end] in node_pairs:
                return ValueError('Edge {} {} already exists'.format(n1, n2))

        self.edges.append(Edge(start=n1, end=n2, cost=cost))
        if both_ends:
            self.edges.append(Edge(start=n2, end=n1, cost=cost))

    @property
    def neighbours(self):
        neighbours = {vertex: set() for vertex in self.vertices}
        for edge in self.edges:
            neighbours[edge.start].add((edge.end, edge.cost))

        return neighbours

    def dijkstra(self, source, dest):
        assert source in self.vertices, 'Such source node doesn\'t exist'
        distances = {vertex: inf for vertex in self.vertices}
        previous_vertices = {
            vertex: None for vertex in self.vertices
        }
        distances[source] = 0
        vertices = self.vertices.copy()

        while vertices:
            current_vertex = min(
                vertices, key=lambda vertex: distances[vertex])
            vertices.remove(current_vertex)
            if distances[current_vertex] == inf:
                break
            for neighbour, cost in self.neighbours[current_vertex]:
                alternative_route = distances[current_vertex] + cost
                if alternative_route < distances[neighbour]:
                    distances[neighbour] = alternative_route
                    previous_vertices[neighbour] = current_vertex

        path, current_vertex = deque(), dest
        while previous_vertices[current_vertex] is not None:
            path.appendleft(current_vertex)
            current_vertex = previous_vertices[current_vertex]
        if path:
            path.appendleft(current_vertex)
        return distances



N, M = map(int,input().split())
X, Y = map(int,input().split())
X -= 1
Y -= 1
D = []
for _ in range(N):
    D.append(list(map(int,input().split())))
K = []
for _ in range(M):
    P, Q = map(int,input().split())
    P -= 1
    Q -= 1
    K.append((P,Q,sqrt((D[P][0]-D[Q][0])**2+(D[P][1]-D[Q][1])**2)))
    K.append((Q,P,sqrt((D[P][0]-D[Q][0])**2+(D[P][1]-D[Q][1])**2)))
graph = Graph(K)
print(graph.dijkstra(X,Y)[Y])
0