mirror of
https://github.com/krahets/hello-algo.git
synced 2024-12-26 04:16:29 +08:00
62 lines
1.5 KiB
Ruby
62 lines
1.5 KiB
Ruby
|
=begin
|
|||
|
|
File: graph_bfs.rb
|
|||
|
|
Created Time: 2024-04-25
|
|||
|
|
Author: Xuan Khoa Tu Nguyen (ngxktuzkai2000@gmail.com)
|
|||
|
|
=end
|
|||
|
|
|
|||
|
|
require 'set'
|
|||
|
|
require_relative './graph_adjacency_list'
|
|||
|
|
require_relative '../utils/vertex'
|
|||
|
|
|
|||
|
|
### 广度优先遍历 ###
|
|||
|
|
def graph_bfs(graph, start_vet)
|
|||
|
|
# 使用邻接表来表示图，以便获取指定顶点的所有邻接顶点
|
|||
|
|
# 顶点遍历序列
|
|||
|
|
res = []
|
|||
|
|
# 哈希表，用于记录已被访问过的顶点
|
|||
|
|
visited = Set.new([start_vet])
|
|||
|
|
# 队列用于实现 BFS
|
|||
|
|
que = [start_vet]
|
|||
|
|
# 以顶点 vet 为起点，循环直至访问完所有顶点
|
|||
|
|
while que.length > 0
|
|||
|
|
vet = que.shift # 队首顶点出队
|
|||
|
|
res << vet # 记录访问顶点
|
|||
|
|
# 遍历该顶点的所有邻接顶点
|
|||
|
|
for adj_vet in graph.adj_list[vet]
|
|||
|
|
next if visited.include?(adj_vet) # 跳过已被访问的顶点
|
|||
|
|
que << adj_vet # 只入队未访问的顶点
|
|||
|
|
visited.add(adj_vet) # 标记该顶点已被访问
|
|||
|
|
end
|
|||
|
|
end
|
|||
|
|
# 返回顶点遍历序列
|
|||
|
|
res
|
|||
|
|
end
|
|||
|
|
|
|||
|
|
### Driver Code ###
|
|||
|
|
if __FILE__ == $0
|
|||
|
|
# 初始化无向图
|
|||
|
|
v = vals_to_vets([0, 1, 2, 3, 4, 5, 6, 7, 8, 9])
|
|||
|
|
edges = [
|
|||
|
|
[v[0], v[1]],
|
|||
|
|
[v[0], v[3]],
|
|||
|
|
[v[1], v[2]],
|
|||
|
|
[v[1], v[4]],
|
|||
|
|
[v[2], v[5]],
|
|||
|
|
[v[3], v[4]],
|
|||
|
|
[v[3], v[6]],
|
|||
|
|
[v[4], v[5]],
|
|||
|
|
[v[4], v[7]],
|
|||
|
|
[v[5], v[8]],
|
|||
|
|
[v[6], v[7]],
|
|||
|
|
[v[7], v[8]],
|
|||
|
|
]
|
|||
|
|
graph = GraphAdjList.new(edges)
|
|||
|
|
puts "\n初始化后，图为"
|
|||
|
|
graph.__print__
|
|||
|
|
|
|||
|
|
# 广度优先遍历
|
|||
|
|
res = graph_bfs(graph, v.first)
|
|||
|
|
puts "\n广度优先便利（BFS）顶点序列为"
|
|||
|
|
p vets_to_vals(res)
|
|||
|
|
end
|