hello-algo/codes/javascript/chapter_graph/graph_bfs.js
zhuoqinyue 2d421de984
feat: add bfs and dfs for JS and TS (#377)
* add bfs and dfs for JS and TS

* update the type

* Apply suggestions from code review

Co-authored-by: Justin Tse <xiefahit@gmail.com>

* Update graph_dfs.ts

* Update graph_bfs.ts

* Update graph_dfs.ts

* Update graph_bfs.ts

* Update graph_dfs.js

* Update graph_bfs.js

---------

Co-authored-by: steak-zhuo <zhuoqinyue@gmail.com>
Co-authored-by: Yudong Jin <krahets@163.com>
Co-authored-by: Justin Tse <xiefahit@gmail.com>
2023-02-25 01:11:11 +08:00

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/**
* File: graph_bfs.js
* Created Time: 2023-02-21
* Author: Zhuo Qinyue (1403450829@qq.com)
*/
const { GraphAdjList } = require('./graph_adjacency_list');
const { Vertex } = require('../include/Vertex');
/* 广度优先遍历 BFS */
// 使用邻接表来表示图,以便获取指定顶点的所有邻接顶点
const graphBfs = (graph, startVet) => {
// 顶点遍历序列
const res = [];
// 哈希表,用于记录已被访问过的顶点
const visited = new Set();
visited.add(startVet);
// 队列用于实现 BFS
const que = [startVet];
// 以顶点 vet 为起点,循环直至访问完所有顶点
while (que.length) {
const vet = que.shift(); // 队首顶点出队
res.push(vet); // 记录访问顶点
// 遍历该顶点的所有邻接顶点
for (const adjVet of graph.adjList.get(vet) ?? []) {
if (visited.has(adjVet)) {
continue; // 跳过已被访问过的顶点
}
que.push(adjVet); // 只入队未访问的顶点
visited.add(adjVet); // 标记该顶点已被访问
}
}
// 返回顶点遍历序列
return res;
}
/* Driver Code */
/* 初始化无向图 */
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初始化后图为");
graph.print();
/* 广度优先遍历 BFS */
const res = graphBfs(graph, v[0]);
console.log("\n广度优先遍历BFS顶点序列为");
console.log(Vertex.vetsToVals(res));