hello-algo/codes/kotlin/chapter_graph/graph_adjacency_list.kt
curtishd 4d9bbe72e1
Improve the consistency between code and comments in Kotlin (#1268)
* style(kotlin): Make code and comments consistent.

* style(kotlin): convert comment location.

* style(c): Add missing comment.

* style(kotlin): Remove redundant semicolon, parenthesis and brace

* style(kotlin): Put constants inside the function.

* style(kotlin): fix unnecessary indentation.

* style(swift): Add missing comment.

* style(kotlin): Add missing comment.

* style(kotlin): Remove redundant comment.

* style(kotlin): Add missing comment.

* Update linked_list.kt

* style(csharp,js,ts): Add missing comment.

* style(kotlin): Remove empty lines.

* Update list.cs

* Update list.js

* Update list.ts

* roll back to commit 1

* style(cs,js,ts): Add missing comment in docfile.

* style(kotlin): Use normal element swapping instead of scope functions.
2024-04-13 20:09:39 +08:00

121 lines
No EOL
3.1 KiB
Kotlin
Raw Blame History

This file contains ambiguous Unicode characters

This file contains Unicode characters that might be confused with other characters. If you think that this is intentional, you can safely ignore this warning. Use the Escape button to reveal them.

/**
* File: graph_adjacency_list.kt
* Created Time: 2024-01-25
* Author: curtishd (1023632660@qq.com)
*/
package chapter_graph
import utils.Vertex
/* 基于邻接表实现的无向图类 */
class GraphAdjList(edges: Array<Array<Vertex?>>) {
// 邻接表key顶点value该顶点的所有邻接顶点
val adjList = HashMap<Vertex, MutableList<Vertex>>()
/* 构造方法 */
init {
// 添加所有顶点和边
for (edge in edges) {
addVertex(edge[0]!!)
addVertex(edge[1]!!)
addEdge(edge[0]!!, edge[1]!!)
}
}
/* 获取顶点数量 */
fun size(): Int {
return adjList.size
}
/* 添加边 */
fun addEdge(vet1: Vertex, vet2: Vertex) {
if (!adjList.containsKey(vet1) || !adjList.containsKey(vet2) || vet1 == vet2)
throw IllegalArgumentException()
// 添加边 vet1 - vet2
adjList[vet1]?.add(vet2)
adjList[vet2]?.add(vet1)
}
/* 删除边 */
fun removeEdge(vet1: Vertex, vet2: Vertex) {
if (!adjList.containsKey(vet1) || !adjList.containsKey(vet2) || vet1 == vet2)
throw IllegalArgumentException()
// 删除边 vet1 - vet2
adjList[vet1]?.remove(vet2)
adjList[vet2]?.remove(vet1)
}
/* 添加顶点 */
fun addVertex(vet: Vertex) {
if (adjList.containsKey(vet))
return
// 在邻接表中添加一个新链表
adjList[vet] = mutableListOf()
}
/* 删除顶点 */
fun removeVertex(vet: Vertex) {
if (!adjList.containsKey(vet))
throw IllegalArgumentException()
// 在邻接表中删除顶点 vet 对应的链表
adjList.remove(vet)
// 遍历其他顶点的链表,删除所有包含 vet 的边
for (list in adjList.values) {
list.remove(vet)
}
}
/* 打印邻接表 */
fun print() {
println("邻接表 =")
for (pair in adjList.entries) {
val tmp = mutableListOf<Int>()
for (vertex in pair.value) {
tmp.add(vertex._val)
}
println("${pair.key._val}: $tmp,")
}
}
}
/* Driver Code */
fun main() {
/* 初始化无向图 */
val v = Vertex.valsToVets(intArrayOf(1, 3, 2, 5, 4))
val edges = arrayOf(
arrayOf(v[0], v[1]),
arrayOf(v[0], v[3]),
arrayOf(v[1], v[2]),
arrayOf(v[2], v[3]),
arrayOf(v[2], v[4]),
arrayOf(v[3], v[4])
)
val graph = GraphAdjList(edges)
println("\n初始化后,图为")
graph.print()
/* 添加边 */
// 顶点 1, 2 即 v[0], v[2]
graph.addEdge(v[0]!!, v[2]!!)
println("\n添加边 1-2 后,图为")
graph.print()
/* 删除边 */
// 顶点 1, 3 即 v[0], v[1]
graph.removeEdge(v[0]!!, v[1]!!)
println("\n删除边 1-3 后,图为")
graph.print()
/* 添加顶点 */
val v5 = Vertex(6)
graph.addVertex(v5)
println("\n添加顶点 6 后,图为")
graph.print()
/* 删除顶点 */
// 顶点 3 即 v[1]
graph.removeVertex(v[1]!!)
println("\n删除顶点 3 后,图为")
graph.print()
}