mirror of
https://github.com/krahets/hello-algo.git
synced 2024-12-28 16:56:29 +08:00
62 lines
1.7 KiB
JavaScript
62 lines
1.7 KiB
JavaScript
|
/**
|
|||
|
|
* File: graph_bfs.js
|
|||
|
|
* Created Time: 2023-02-21
|
|||
|
|
* Author: Zhuo Qinyue (1403450829@qq.com)
|
|||
|
|
*/
|
|||
|
|
|
|||
|
|
const { GraphAdjList } = require('./graph_adjacency_list');
|
|||
|
|
const { Vertex } = require('../modules/Vertex');
|
|||
|
|
|
|||
|
|
/* 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
|
|||
|
|
function graphBFS(graph, startVet) {
|
|||
|
|
// 頂點走訪序列
|
|||
|
|
const res = [];
|
|||
|
|
// 雜湊表，用於記錄已被訪問過的頂點
|
|||
|
|
const visited = new Set();
|
|||
|
|
visited.add(startVet);
|
|||
|
|
// 佇列用於實現 BFS
|
|||
|
|
const que = [startVet];
|
|||
|
|
// 以頂點 vet 為起點，迴圈直至訪問完所有頂點
|
|||
|
|
while (que.length) {
|
|||
|
|
const vet = que.shift(); // 佇列首頂點出隊
|
|||
|
|
res.push(vet); // 記錄訪問頂點
|
|||
|
|
// 走訪該頂點的所有鄰接頂點
|
|||
|
|
for (const adjVet of graph.adjList.get(vet) ?? []) {
|
|||
|
|
if (visited.has(adjVet)) {
|
|||
|
|
continue; // 跳過已被訪問的頂點
|
|||
|
|
}
|
|||
|
|
que.push(adjVet); // 只入列未訪問的頂點
|
|||
|
|
visited.add(adjVet); // 標記該頂點已被訪問
|
|||
|
|
}
|
|||
|
|
}
|
|||
|
|
// 返回頂點走訪序列
|
|||
|
|
return res;
|
|||
|
|
}
|
|||
|
|
|
|||
|
|
/* Driver Code */
|
|||
|
|
/* 初始化無向圖 */
|
|||
|
|
const v = Vertex.valsToVets([0, 1, 2, 3, 4, 5, 6, 7, 8, 9]);
|
|||
|
|
const 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]],
|
|||
|
|
];
|
|||
|
|
const graph = new GraphAdjList(edges);
|
|||
|
|
console.log('\n初始化後，圖為');
|
|||
|
|
graph.print();
|
|||
|
|
|
|||
|
|
/* 廣度優先走訪 */
|
|||
|
|
const res = graphBFS(graph, v[0]);
|
|||
|
|
console.log('\n廣度優先走訪（BFS）頂點序列為');
|
|||
|
|
console.log(Vertex.vetsToVals(res));
|