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61 lines
1.7 KiB
JavaScript
61 lines
1.7 KiB
JavaScript
/**
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* File: graph_bfs.js
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* Created Time: 2023-02-21
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* Author: Zhuo Qinyue (1403450829@qq.com)
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*/
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const { GraphAdjList } = require('./graph_adjacency_list');
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const { Vertex } = require('../modules/Vertex');
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/* 广度优先遍历 BFS */
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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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function graphBFS(graph, startVet) {
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// 顶点遍历序列
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const res = [];
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// 哈希表，用于记录已被访问过的顶点
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const visited = new Set();
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visited.add(startVet);
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// 队列用于实现 BFS
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const que = [startVet];
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// 以顶点 vet 为起点，循环直至访问完所有顶点
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while (que.length) {
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const vet = que.shift(); // 队首顶点出队
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res.push(vet); // 记录访问顶点
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// 遍历该顶点的所有邻接顶点
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for (const adjVet of graph.adjList.get(vet) ?? []) {
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if (visited.has(adjVet)) {
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continue; // 跳过已被访问过的顶点
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}
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que.push(adjVet); // 只入队未访问的顶点
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visited.add(adjVet); // 标记该顶点已被访问
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}
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}
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// 返回顶点遍历序列
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return res;
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}
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/* Driver Code */
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/* 初始化无向图 */
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const v = Vertex.valsToVets([0, 1, 2, 3, 4, 5, 6, 7, 8, 9]);
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const edges = [
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[v[0], v[1]],
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[v[0], v[3]],
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[v[1], v[2]],
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[v[1], v[4]],
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[v[2], v[5]],
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[v[3], v[4]],
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[v[3], v[6]],
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[v[4], v[5]],
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[v[4], v[7]],
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[v[5], v[8]],
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[v[6], v[7]],
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[v[7], v[8]],
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];
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const graph = new GraphAdjList(edges);
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console.log('\n初始化后，图为');
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graph.print();
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/* 广度优先遍历 BFS */
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const res = graphBFS(graph, v[0]);
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console.log('\n广度优先遍历（BFS）顶点序列为');
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console.log(Vertex.vetsToVals(res));
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