mirror of
https://github.com/krahets/hello-algo.git
synced 2024-12-27 04:36:29 +08:00
110 lines
3 KiB
Python
110 lines
3 KiB
Python
"""
|
||
File: graph_adjacency_list.py
|
||
Created Time: 2023-02-23
|
||
Author: Krahets (krahets@163.com)
|
||
"""
|
||
|
||
import sys, os.path as osp
|
||
|
||
sys.path.append(osp.dirname(osp.dirname(osp.abspath(__file__))))
|
||
from modules import *
|
||
|
||
|
||
class GraphAdjList:
|
||
"""基于邻接表实现的无向图类"""
|
||
|
||
def __init__(self, edges: list[list[Vertex]]):
|
||
"""构造方法"""
|
||
# 邻接表，key: 顶点，value：该顶点的所有邻接顶点
|
||
self.adj_list = dict[Vertex, list[Vertex]]()
|
||
# 添加所有顶点和边
|
||
for edge in edges:
|
||
self.add_vertex(edge[0])
|
||
self.add_vertex(edge[1])
|
||
self.add_edge(edge[0], edge[1])
|
||
|
||
def size(self) -> int:
|
||
"""获取顶点数量"""
|
||
return len(self.adj_list)
|
||
|
||
def add_edge(self, vet1: Vertex, vet2: Vertex):
|
||
"""添加边"""
|
||
if vet1 not in self.adj_list or vet2 not in self.adj_list or vet1 == vet2:
|
||
raise ValueError()
|
||
# 添加边 vet1 - vet2
|
||
self.adj_list[vet1].append(vet2)
|
||
self.adj_list[vet2].append(vet1)
|
||
|
||
def remove_edge(self, vet1: Vertex, vet2: Vertex):
|
||
"""删除边"""
|
||
if vet1 not in self.adj_list or vet2 not in self.adj_list or vet1 == vet2:
|
||
raise ValueError()
|
||
# 删除边 vet1 - vet2
|
||
self.adj_list[vet1].remove(vet2)
|
||
self.adj_list[vet2].remove(vet1)
|
||
|
||
def add_vertex(self, vet: Vertex):
|
||
"""添加顶点"""
|
||
if vet in self.adj_list:
|
||
return
|
||
# 在邻接表中添加一个新链表
|
||
self.adj_list[vet] = []
|
||
|
||
def remove_vertex(self, vet: Vertex):
|
||
"""删除顶点"""
|
||
if vet not in self.adj_list:
|
||
raise ValueError()
|
||
# 在邻接表中删除顶点 vet 对应的链表
|
||
self.adj_list.pop(vet)
|
||
# 遍历其他顶点的链表，删除所有包含 vet 的边
|
||
for vertex in self.adj_list:
|
||
if vet in self.adj_list[vertex]:
|
||
self.adj_list[vertex].remove(vet)
|
||
|
||
def print(self):
|
||
"""打印邻接表"""
|
||
print("邻接表 =")
|
||
for vertex in self.adj_list:
|
||
tmp = [v.val for v in self.adj_list[vertex]]
|
||
print(f"{vertex.val}: {tmp},")
|
||
|
||
|
||
"""Driver Code"""
|
||
if __name__ == "__main__":
|
||
# 初始化无向图
|
||
v = vals_to_vets([1, 3, 2, 5, 4])
|
||
edges = [
|
||
[v[0], v[1]],
|
||
[v[0], v[3]],
|
||
[v[1], v[2]],
|
||
[v[2], v[3]],
|
||
[v[2], v[4]],
|
||
[v[3], v[4]],
|
||
]
|
||
graph = GraphAdjList(edges)
|
||
print("\n初始化后，图为")
|
||
graph.print()
|
||
|
||
# 添加边
|
||
# 顶点 1, 2 即 v[0], v[2]
|
||
graph.add_edge(v[0], v[2])
|
||
print("\n添加边 1-2 后，图为")
|
||
graph.print()
|
||
|
||
# 删除边
|
||
# 顶点 1, 3 即 v[0], v[1]
|
||
graph.remove_edge(v[0], v[1])
|
||
print("\n删除边 1-3 后，图为")
|
||
graph.print()
|
||
|
||
# 添加顶点
|
||
v5 = Vertex(6)
|
||
graph.add_vertex(v5)
|
||
print("\n添加顶点 6 后，图为")
|
||
graph.print()
|
||
|
||
# 删除顶点
|
||
# 顶点 3 即 v[1]
|
||
graph.remove_vertex(v[1])
|
||
print("\n删除顶点 3 后，图为")
|
||
graph.print()
|