mirror of
https://github.com/krahets/hello-algo.git
synced 2025-11-04 06:07:20 +08:00
Add kotlin code for the chapter of graph (#1102)
* feat(kotlin): add kotlin code for dynamic programming. * Update knapsack.kt * feat(kotlin): add kotlin codes for graph. * style(kotlin): reformatted the codes.
This commit is contained in:
curtishd
121
codes/kotlin/chapter_graph/graph_adjacency_list.kt
Normal file
121
codes/kotlin/chapter_graph/graph_adjacency_list.kt
Normal file
@ -0,0 +1,121 @@
|
||||
/**
|
||||
* 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: MutableMap<Vertex, MutableList<Vertex>> = HashMap()
|
||||
|
||||
/* 构造函数 */
|
||||
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 = ArrayList<Int>()
|
||||
for (vertex in pair.value) {
|
||||
tmp.add(vertex.value)
|
||||
}
|
||||
println("${pair.key.value}: $tmp,")
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
/* Driver Code */
|
||||
fun main() {
|
||||
/* 初始化无向图 */
|
||||
val v: Array<Vertex?> = 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()
|
||||
}
|
||||
131
codes/kotlin/chapter_graph/graph_adjacency_matrix.kt
Normal file
131
codes/kotlin/chapter_graph/graph_adjacency_matrix.kt
Normal file
@ -0,0 +1,131 @@
|
||||
/**
|
||||
* File: graph_adjacency_matrix.kt
|
||||
* Created Time: 2024-01-25
|
||||
* Author: curtishd (1023632660@qq.com)
|
||||
*/
|
||||
|
||||
package chapter_graph
|
||||
|
||||
import utils.printMatrix
|
||||
|
||||
/* 基于邻接矩阵实现的无向图类 */
|
||||
class GraphAdjMat(vertices: IntArray, edges: Array<IntArray>) {
|
||||
val vertices: MutableList<Int> = ArrayList() // 顶点列表，元素代表“顶点值”，索引代表“顶点索引”
|
||||
val adjMat: MutableList<MutableList<Int>> = ArrayList() // 邻接矩阵，行列索引对应“顶点索引”
|
||||
|
||||
/* 构造函数 */
|
||||
init {
|
||||
// 添加顶点
|
||||
for (vertex in vertices) {
|
||||
addVertex(vertex)
|
||||
}
|
||||
// 添加边
|
||||
// 请注意，edges 元素代表顶点索引，即对应 vertices 元素索引
|
||||
for (edge in edges) {
|
||||
addEdge(edge[0], edge[1])
|
||||
}
|
||||
}
|
||||
|
||||
/* 获取顶点数量 */
|
||||
fun size(): Int {
|
||||
return vertices.size
|
||||
}
|
||||
|
||||
/* 添加顶点 */
|
||||
fun addVertex(value: Int) {
|
||||
val n = size()
|
||||
// 向顶点列表中添加新顶点的值
|
||||
vertices.add(value)
|
||||
// 在邻接矩阵中添加一行
|
||||
val newRow: MutableList<Int> = mutableListOf()
|
||||
for (j in 0..<n) {
|
||||
newRow.add(0)
|
||||
}
|
||||
adjMat.add(newRow)
|
||||
// 在邻接矩阵中添加一列
|
||||
for (row in adjMat) {
|
||||
row.add(0)
|
||||
}
|
||||
}
|
||||
|
||||
/* 删除顶点 */
|
||||
fun removeVertex(index: Int) {
|
||||
if (index >= size()) throw IndexOutOfBoundsException()
|
||||
// 在顶点列表中移除索引 index 的顶点
|
||||
vertices.removeAt(index)
|
||||
// 在邻接矩阵中删除索引 index 的行
|
||||
adjMat.removeAt(index)
|
||||
// 在邻接矩阵中删除索引 index 的列
|
||||
for (row in adjMat) {
|
||||
row.removeAt(index)
|
||||
}
|
||||
}
|
||||
|
||||
/* 添加边 */
|
||||
// 参数 i, j 对应 vertices 元素索引
|
||||
fun addEdge(i: Int, j: Int) {
|
||||
// 索引越界与相等处理
|
||||
if (i < 0 || j < 0 || i >= size() || j >= size() || i == j) throw java.lang.IndexOutOfBoundsException()
|
||||
// 在无向图中，邻接矩阵关于主对角线对称，即满足 (i, j) == (j, i)
|
||||
adjMat[i][j] = 1;
|
||||
adjMat[j][i] = 1;
|
||||
}
|
||||
|
||||
/* 删除边 */
|
||||
// 参数 i, j 对应 vertices 元素索引
|
||||
fun removeEdge(i: Int, j: Int) {
|
||||
// 索引越界与相等处理
|
||||
if (i < 0 || j < 0 || i >= size() || j >= size() || i == j) throw java.lang.IndexOutOfBoundsException()
|
||||
adjMat[i][j] = 0;
|
||||
adjMat[j][i] = 0;
|
||||
}
|
||||
|
||||
/* 打印邻接矩阵 */
|
||||
fun print() {
|
||||
print("顶点列表 = ")
|
||||
println(vertices);
|
||||
println("邻接矩阵 =");
|
||||
printMatrix(adjMat)
|
||||
}
|
||||
}
|
||||
|
||||
/* Driver Code */
|
||||
fun main() {
|
||||
/* 初始化无向图 */
|
||||
// 请注意，edges 元素代表顶点索引，即对应 vertices 元素索引
|
||||
val vertices = intArrayOf(1, 3, 2, 5, 4)
|
||||
val edges = arrayOf(
|
||||
intArrayOf(0, 1),
|
||||
intArrayOf(0, 3),
|
||||
intArrayOf(1, 2),
|
||||
intArrayOf(2, 3),
|
||||
intArrayOf(2, 4),
|
||||
intArrayOf(3, 4)
|
||||
)
|
||||
val graph = GraphAdjMat(vertices, edges)
|
||||
println("\n初始化后，图为")
|
||||
graph.print()
|
||||
|
||||
/* 添加边 */
|
||||
// 顶点 1, 2 的索引分别为 0, 2
|
||||
graph.addEdge(0, 2)
|
||||
println("\n添加边 1-2 后，图为")
|
||||
graph.print()
|
||||
|
||||
/* 删除边 */
|
||||
// 顶点 1, 3 的索引分别为 0, 1
|
||||
graph.removeEdge(0, 1)
|
||||
println("\n删除边 1-3 后，图为")
|
||||
graph.print()
|
||||
|
||||
/* 添加顶点 */
|
||||
graph.addVertex(6)
|
||||
println("\n添加顶点 6 后，图为")
|
||||
graph.print()
|
||||
|
||||
/* 删除顶点 */
|
||||
// 顶点 3 的索引为 1
|
||||
graph.removeVertex(1)
|
||||
println("\n删除顶点 3 后，图为")
|
||||
graph.print()
|
||||
}
|
||||
65
codes/kotlin/chapter_graph/graph_bfs.kt
Normal file
65
codes/kotlin/chapter_graph/graph_bfs.kt
Normal file
@ -0,0 +1,65 @@
|
||||
/**
|
||||
* File: graph_bfs.kt
|
||||
* Created Time: 2024-01-25
|
||||
* Author: curtishd (1023632660@qq.com)
|
||||
*/
|
||||
|
||||
package chapter_graph
|
||||
|
||||
import utils.Vertex
|
||||
import java.util.*
|
||||
|
||||
/* 广度优先遍历 */
|
||||
// 使用邻接表来表示图，以便获取指定顶点的所有邻接顶点
|
||||
fun graphBFS(graph: GraphAdjList, startVet: Vertex): List<Vertex> {
|
||||
// 顶点遍历序列
|
||||
val res: MutableList<Vertex> = ArrayList()
|
||||
// 哈希表，用于记录已被访问过的顶点
|
||||
val visited: MutableSet<Vertex> = HashSet()
|
||||
visited.add(startVet)
|
||||
// 队列用于实现 BFS
|
||||
val que: Queue<Vertex> = LinkedList()
|
||||
que.offer(startVet)
|
||||
// 以顶点 vet 为起点，循环直至访问完所有顶点
|
||||
while (!que.isEmpty()) {
|
||||
val vet = que.poll() // 队首顶点出队
|
||||
res.add(vet) // 记录访问顶点
|
||||
// 遍历该顶点的所有邻接顶点
|
||||
for (adjVet in graph.adjList[vet]!!) {
|
||||
if (visited.contains(adjVet)) continue // 跳过已被访问的顶点
|
||||
|
||||
que.offer(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 */
|
||||
fun main() {
|
||||
/* 初始化无向图 */
|
||||
val v = Vertex.valsToVets(intArrayOf(0, 1, 2, 3, 4, 5, 6, 7, 8, 9))
|
||||
val edges = arrayOf(
|
||||
arrayOf(v[0], v[1]),
|
||||
arrayOf(v[0], v[3]),
|
||||
arrayOf(v[1], v[2]),
|
||||
arrayOf(v[1], v[4]),
|
||||
arrayOf(v[2], v[5]),
|
||||
arrayOf(v[3], v[4]),
|
||||
arrayOf(v[3], v[6]),
|
||||
arrayOf(v[4], v[5]),
|
||||
arrayOf(v[4], v[7]),
|
||||
arrayOf(v[5], v[8]),
|
||||
arrayOf(v[6], v[7]),
|
||||
arrayOf(v[7], v[8])
|
||||
)
|
||||
val graph = GraphAdjList(edges)
|
||||
println("\n初始化后，图为")
|
||||
graph.print()
|
||||
|
||||
/* 广度优先遍历 */
|
||||
val res = graphBFS(graph, v[0]!!)
|
||||
println("\n广度优先遍历（BFS）顶点序列为")
|
||||
println(Vertex.vetsToVals(res))
|
||||
}
|
||||
62
codes/kotlin/chapter_graph/graph_dfs.kt
Normal file
62
codes/kotlin/chapter_graph/graph_dfs.kt
Normal file
@ -0,0 +1,62 @@
|
||||
/**
|
||||
* File: graph_dfs.kt
|
||||
* Created Time: 2024-01-25
|
||||
* Author: curtishd (1023632660@qq.com)
|
||||
*/
|
||||
|
||||
package chapter_graph
|
||||
|
||||
import utils.Vertex
|
||||
|
||||
/* 深度优先遍历辅助函数 */
|
||||
fun dfs(
|
||||
graph: GraphAdjList,
|
||||
visited: MutableSet<Vertex?>,
|
||||
res: MutableList<Vertex?>,
|
||||
vet: Vertex?
|
||||
) {
|
||||
res.add(vet) // 记录访问顶点
|
||||
visited.add(vet) // 标记该顶点已被访问
|
||||
// 遍历该顶点的所有邻接顶点
|
||||
for (adjVet in graph.adjList[vet]!!) {
|
||||
if (visited.contains(adjVet)) continue // 跳过已被访问的顶点
|
||||
// 递归访问邻接顶点
|
||||
dfs(graph, visited, res, adjVet)
|
||||
}
|
||||
}
|
||||
|
||||
/* 深度优先遍历 */
|
||||
// 使用邻接表来表示图，以便获取指定顶点的所有邻接顶点
|
||||
fun graphDFS(
|
||||
graph: GraphAdjList,
|
||||
startVet: Vertex?
|
||||
): List<Vertex?> {
|
||||
// 顶点遍历序列
|
||||
val res: MutableList<Vertex?> = ArrayList()
|
||||
// 哈希表，用于记录已被访问过的顶点
|
||||
val visited: MutableSet<Vertex?> = HashSet()
|
||||
dfs(graph, visited, res, startVet)
|
||||
return res
|
||||
}
|
||||
|
||||
/* Driver Code */
|
||||
fun main() {
|
||||
/* 初始化无向图 */
|
||||
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初始化后，图为")
|
||||
graph.print()
|
||||
|
||||
/* 深度优先遍历 */
|
||||
val res = graphDFS(graph, v[0])
|
||||
println("\n深度优先遍历（DFS）顶点序列为")
|
||||
println(Vertex.vetsToVals(res))
|
||||
}
|
||||
Reference in New Issue
Block a user