拓扑排序算法(DFS)的Python实现

from collections import defaultdict

class Graph:
    def __init__(self, num_vertices):
        self.graph = defaultdict(list)
        self.num_vertices = num_vertices

    def add_edge(self, u, v):
        self.graph[u].append(v)

    def topological_sort_util(self, v, visited, stack):
        visited[v] = True

        for i in self.graph[v]:
            if visited[i] == False:
                self.topological_sort_util(i, visited, stack)

        stack.insert(0, v)

    def topological_sort(self):
        visited = [False] * self.num_vertices
        stack = []

        for i in range(self.num_vertices):
            if visited[i] == False:
                self.topological_sort_util(i, visited, stack)

        return stack

# 创建一个有向图
g = Graph(6)
g.add_edge(5, 2)
g.add_edge(5, 0)
g.add_edge(4, 0)
g.add_edge(4, 1)
g.add_edge(2, 3)
g.add_edge(3, 1)

print("拓扑排序结果：", g.topological_sort())