hello-algo/zh-hant/codes/kotlin/chapter_graph/graph_dfs.kt
Yudong Jin 870e3e5cb2
Bug fixes and improvements (#1318)
* 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
2024-04-30 15:52:05 +08:00

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/**
* File: graph_dfs.kt
* Created Time: 2024-01-25
* Author: curtishd (1023632660@qq.com)
*/
package chapter_graph
import utils.Vertex
/* 深度優先走訪輔助函式 */
fun dfs(
graph: GraphAdjList,
visited: MutableSet<Vertex?>,
res: MutableList<Vertex?>,
vet: Vertex?
) {
res.add(vet) // 記錄訪問頂點
visited.add(vet) // 標記該頂點已被訪問
// 走訪該頂點的所有鄰接頂點
for (adjVet in graph.adjList[vet]!!) {
if (visited.contains(adjVet))
continue // 跳過已被訪問的頂點
// 遞迴訪問鄰接頂點
dfs(graph, visited, res, adjVet)
}
}
/* 深度優先走訪 */
// 使用鄰接表來表示圖,以便獲取指定頂點的所有鄰接頂點
fun graphDFS(graph: GraphAdjList, startVet: Vertex?): MutableList<Vertex?> {
// 頂點走訪序列
val res = mutableListOf<Vertex?>()
// 雜湊集合,用於記錄已被訪問過的頂點
val visited = HashSet<Vertex?>()
dfs(graph, visited, res, startVet)
return res
}
/* Driver Code */
fun main() {
/* 初始化無向圖 */
val v = Vertex.valsToVets(intArrayOf(0, 1, 2, 3, 4, 5, 6))
val edges = arrayOf(
arrayOf(v[0], v[1]),
arrayOf(v[0], v[3]),
arrayOf(v[1], v[2]),
arrayOf(v[2], v[5]),
arrayOf(v[4], v[5]),
arrayOf(v[5], v[6])
)
val graph = GraphAdjList(edges)
println("\n初始化後,圖為")
graph.print()
/* 深度優先走訪 */
val res = graphDFS(graph, v[0])
println("\n深度優先走訪DFS頂點序列為")
println(Vertex.vetsToVals(res))
}