mirror of
https://github.com/krahets/hello-algo.git
synced 2026-06-15 22:57:48 +08:00
55 lines
1.4 KiB
Ruby
55 lines
1.4 KiB
Ruby
=begin
|
||
File: graph_dfs.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'
|
||
|
||
### 深さ優先探索の補助関数 ###
|
||
def dfs(graph, visited, res, vet)
|
||
res << vet # 訪問した頂点を記録
|
||
visited.add(vet) # この頂点を訪問済みにする
|
||
# この頂点のすべての隣接頂点を走査
|
||
for adj_vet in graph.adj_list[vet]
|
||
next if visited.include?(adj_vet) # 訪問済みの頂点をスキップ
|
||
# 隣接頂点を再帰的に訪問
|
||
dfs(graph, visited, res, adj_vet)
|
||
end
|
||
end
|
||
|
||
### 深さ優先探索 ###
|
||
def graph_dfs(graph, start_vet)
|
||
# 指定した頂点の隣接頂点をすべて取得できるよう、隣接リストでグラフを表現する
|
||
# 頂点の走査順序
|
||
res = []
|
||
# 訪問済み頂点を記録するためのハッシュ集合
|
||
visited = Set.new
|
||
dfs(graph, visited, res, start_vet)
|
||
res
|
||
end
|
||
|
||
### Driver Code ###
|
||
if __FILE__ == $0
|
||
# 無向グラフを初期化
|
||
v = vals_to_vets([0, 1, 2, 3, 4, 5, 6])
|
||
edges = [
|
||
[v[0], v[1]],
|
||
[v[0], v[3]],
|
||
[v[1], v[2]],
|
||
[v[2], v[5]],
|
||
[v[4], v[5]],
|
||
[v[5], v[6]],
|
||
]
|
||
graph = GraphAdjList.new(edges)
|
||
puts "\n初期化後のグラフは"
|
||
graph.__print__
|
||
|
||
# 深さ優先探索
|
||
res = graph_dfs(graph, v[0])
|
||
puts "\n深さ優先探索（DFS）の頂点順序は"
|
||
p vets_to_vals(res)
|
||
end
|