python无向图有向图基本操作

最新推荐文章于 2024-05-18 08:44:25 发布

原创

最新推荐文章于 2024-05-18 08:44:25 发布 · 367 阅读

1 ·

CC 4.0 BY-SA版权

文章标签：

#python

文章详细讲解了如何用Python构建有向和无向图，包括邻接矩阵和邻接表的使用，以及深度优先和广度优先搜索算法的应用。最后展示了最小生成树的构建过程。

from queue import Queue
import sys


class DirectedGraph:
    def __init__(self, num_vertices):
        self.num_vertices = num_vertices
        self.adj_matrix = [[0] * num_vertices for _ in range(num_vertices)]
        self.adj_list = [[] for _ in range(num_vertices)]

    def add_edge(self, start_vertex, end_vertex, weight=1):
        if 0 <= start_vertex < self.num_vertices and 0 <= end_vertex < self.num_vertices:
            self.adj_matrix[start_vertex][end_vertex] = weight
            self.adj_list[start_vertex].append((end_vertex, weight))

    def remove_edge(self, start_vertex, end_vertex):
        if 0 <= start_vertex < self.num_vertices and 0 <= end_vertex < self.num_vertices:
            self.adj_matrix[start_vertex][end_vertex] = 0
            self.adj_list[start_vertex] = [(v, w) for v, w in self.adj_list[start_vertex] if v != end_vertex]

    @classmethod
    def from_adjacency_matrix(cls, adj_matrix):
        num_vertices = len(adj_matrix)
        graph = cls(num_vertices)
        for i in range(num_vertices):
            for j in range(num_vertices):
                weight = adj_matrix[i][j]
                if weight != 0:
                    graph.add_edge(i, j, weight)
        return graph

    @classmethod
    def from_adjacency_list(cls, adj_list):
        num_vertices = len(adj_list)
        graph = cls(num_vertices)
        for start_vertex, neighbors in enumerate