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
2.0 KiB
C++
60 lines
2.0 KiB
C++
/**
|
||
* File: graph_bfs.cpp
|
||
* Created Time: 2023-03-02
|
||
* Author: krahets (krahets@163.com)
|
||
*/
|
||
|
||
#include "../utils/common.hpp"
|
||
#include "./graph_adjacency_list.cpp"
|
||
|
||
/* 廣度優先走訪 */
|
||
// 使用鄰接表來表示圖，以便獲取指定頂點的所有鄰接頂點
|
||
vector<Vertex *> graphBFS(GraphAdjList &graph, Vertex *startVet) {
|
||
// 頂點走訪序列
|
||
vector<Vertex *> res;
|
||
// 雜湊集合，用於記錄已被訪問過的頂點
|
||
unordered_set<Vertex *> visited = {startVet};
|
||
// 佇列用於實現 BFS
|
||
queue<Vertex *> que;
|
||
que.push(startVet);
|
||
// 以頂點 vet 為起點，迴圈直至訪問完所有頂點
|
||
while (!que.empty()) {
|
||
Vertex *vet = que.front();
|
||
que.pop(); // 佇列首頂點出隊
|
||
res.push_back(vet); // 記錄訪問頂點
|
||
// 走訪該頂點的所有鄰接頂點
|
||
for (auto adjVet : graph.adjList[vet]) {
|
||
if (visited.count(adjVet))
|
||
continue; // 跳過已被訪問的頂點
|
||
que.push(adjVet); // 只入列未訪問的頂點
|
||
visited.emplace(adjVet); // 標記該頂點已被訪問
|
||
}
|
||
}
|
||
// 返回頂點走訪序列
|
||
return res;
|
||
}
|
||
|
||
/* Driver Code */
|
||
int main() {
|
||
/* 初始化無向圖 */
|
||
vector<Vertex *> v = valsToVets({0, 1, 2, 3, 4, 5, 6, 7, 8, 9});
|
||
vector<vector<Vertex *>> 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]}};
|
||
GraphAdjList graph(edges);
|
||
cout << "\n初始化後，圖為\\n";
|
||
graph.print();
|
||
|
||
/* 廣度優先走訪 */
|
||
vector<Vertex *> res = graphBFS(graph, v[0]);
|
||
cout << "\n廣度優先走訪（BFS）頂點序列為" << endl;
|
||
printVector(vetsToVals(res));
|
||
|
||
// 釋放記憶體
|
||
for (Vertex *vet : v) {
|
||
delete vet;
|
||
}
|
||
|
||
return 0;
|
||
}
|