37 lines
1.1 KiB
Go
37 lines
1.1 KiB
Go
// File: graph_dfs.go
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// Created Time: 2023-02-18
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// Author: Reanon (793584285@qq.com)
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package chapter_graph
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import (
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. "github.com/krahets/hello-algo/pkg"
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)
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/* Depth-first traversal helper function */
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func dfs(g *graphAdjList, visited map[Vertex]struct{}, res *[]Vertex, vet Vertex) {
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// The append operation returns a new reference, the original reference must be reassigned to the new slice reference
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*res = append(*res, vet)
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visited[vet] = struct{}{}
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// Traverse all adjacent vertices of that vertex
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for _, adjVet := range g.adjList[vet] {
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_, isExist := visited[adjVet]
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// Recursively visit adjacent vertices
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if !isExist {
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dfs(g, visited, res, adjVet)
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}
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}
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}
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/* Depth-first traversal */
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// Use adjacency list to represent the graph, to obtain all adjacent vertices of a specified vertex
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func graphDFS(g *graphAdjList, startVet Vertex) []Vertex {
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// Vertex traversal sequence
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res := make([]Vertex, 0)
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// Hash set, used to record visited vertices
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visited := make(map[Vertex]struct{})
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dfs(g, visited, &res, startVet)
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// Return the vertex traversal sequence
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return res
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}
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