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/**
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* File: graph_dfs.cpp
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* Created Time: 2023-03-02
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* Author: krahets (krahets@163.com)
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*/
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#include "../utils/common.hpp"
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#include "./graph_adjacency_list.cpp"
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/* 深度优先遍历辅助函数 */
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void dfs(GraphAdjList &graph, unordered_set<Vertex *> &visited, vector<Vertex *> &res, Vertex *vet) {
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res.push_back(vet); // 记录访问顶点
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visited.emplace(vet); // 标记该顶点已被访问
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// 遍历该顶点的所有邻接顶点
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for (Vertex *adjVet : graph.adjList[vet]) {
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if (visited.count(adjVet))
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continue; // 跳过已被访问的顶点
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// 递归访问邻接顶点
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dfs(graph, visited, res, adjVet);
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}
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}
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/* 深度优先遍历 */
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// 使用邻接表来表示图，以便获取指定顶点的所有邻接顶点
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vector<Vertex *> graphDFS(GraphAdjList &graph, Vertex *startVet) {
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// 顶点遍历序列
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vector<Vertex *> res;
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// 哈希集合，用于记录已被访问过的顶点
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unordered_set<Vertex *> visited;
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dfs(graph, visited, res, startVet);
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return res;
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}
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/* Driver Code */
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int main() {
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/* 初始化无向图 */
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vector<Vertex *> v = valsToVets(vector<int>{0, 1, 2, 3, 4, 5, 6});
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vector<vector<Vertex *>> edges = {{v[0], v[1]}, {v[0], v[3]}, {v[1], v[2]},
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{v[2], v[5]}, {v[4], v[5]}, {v[5], v[6]}};
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GraphAdjList graph(edges);
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cout << "\n初始化后，图为" << endl;
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graph.print();
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/* 深度优先遍历 */
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vector<Vertex *> res = graphDFS(graph, v[0]);
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cout << "\n深度优先遍历（DFS）顶点序列为" << endl;
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printVector(vetsToVals(res));
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// 释放内存
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for (Vertex *vet : v) {
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delete vet;
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}
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return 0;
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}
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