mirror of
https://github.com/krahets/hello-algo.git
synced 2025-10-31 18:37:48 +08:00
870e3e5cb2
* Sync zh and zh-hant versions * Update en/README.md * Add a Q&A for chapter of introduction * Update the callout headers * Sync zh ang zh-hant versions * Bug fixes
60 lines
1.4 KiB
Dart
60 lines
1.4 KiB
Dart
/**
|
||
* File: graph_dfs.dart
|
||
* Created Time: 2023-05-15
|
||
* Author: liuyuxin (gvenusleo@gmail.com)
|
||
*/
|
||
|
||
import '../utils/vertex.dart';
|
||
import 'graph_adjacency_list.dart';
|
||
|
||
/* 深度優先走訪輔助函式 */
|
||
void dfs(
|
||
GraphAdjList graph,
|
||
Set<Vertex> visited,
|
||
List<Vertex> res,
|
||
Vertex vet,
|
||
) {
|
||
res.add(vet); // 記錄訪問頂點
|
||
visited.add(vet); // 標記該頂點已被訪問
|
||
// 走訪該頂點的所有鄰接頂點
|
||
for (Vertex adjVet in graph.adjList[vet]!) {
|
||
if (visited.contains(adjVet)) {
|
||
continue; // 跳過已被訪問的頂點
|
||
}
|
||
// 遞迴訪問鄰接頂點
|
||
dfs(graph, visited, res, adjVet);
|
||
}
|
||
}
|
||
|
||
/* 深度優先走訪 */
|
||
List<Vertex> graphDFS(GraphAdjList graph, Vertex startVet) {
|
||
// 頂點走訪序列
|
||
List<Vertex> res = [];
|
||
// 雜湊集合，用於記錄已被訪問過的頂點
|
||
Set<Vertex> visited = {};
|
||
dfs(graph, visited, res, startVet);
|
||
return res;
|
||
}
|
||
|
||
/* Driver Code */
|
||
void main() {
|
||
/* 初始化無向圖 */
|
||
List<Vertex> v = Vertex.valsToVets([0, 1, 2, 3, 4, 5, 6]);
|
||
List<List<Vertex>> 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]],
|
||
];
|
||
GraphAdjList graph = GraphAdjList(edges);
|
||
print("\n初始化後，圖為");
|
||
graph.printAdjList();
|
||
|
||
/* 深度優先走訪 */
|
||
List<Vertex> res = graphDFS(graph, v[0]);
|
||
print("\n深度優先走訪（DFS）頂點序列為");
|
||
print(Vertex.vetsToVals(res));
|
||
}
|