hello-algo/codes/dart/chapter_graph/graph_dfs.dart

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/**
* File: graph_dfs.dart
* Created Time: 2023-05-15
* Author: liuyuxin (gvenusleo@gmail.com)
*/
import '../utils/vertex.dart';
import 'graph_adjacency_list.dart';
/* 深度优先遍历辅助函数 */
void dfs(
GraphAdjList graph,
Set<Vertex> visited,
List<Vertex> res,
Vertex vet,
) {
res.add(vet); // 记录访问顶点
visited.add(vet); // 标记该顶点已被访问
// 遍历该顶点的所有邻接顶点
for (Vertex adjVet in graph.adjList[vet]!) {
if (visited.contains(adjVet)) {
continue; // 跳过已被访问的顶点
}
// 递归访问邻接顶点
dfs(graph, visited, res, adjVet);
}
}
/* 深度优先遍历 */
List<Vertex> graphDFS(GraphAdjList graph, Vertex startVet) {
// 顶点遍历序列
List<Vertex> res = [];
// 哈希集合,用于记录已被访问过的顶点
Set<Vertex> visited = {};
dfs(graph, visited, res, startVet);
return res;
}
/* Driver Code */
void main() {
/* 初始化无向图 */
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初始化后,图为");
graph.printAdjList();
/* 深度优先遍历 */
List<Vertex> res = graphDFS(graph, v[0]);
print("\n深度优先遍历DFS顶点序列为");
print(Vertex.vetsToVals(res));
}