lm-tecniche-di-programmazione/src/main/kotlin/it/norangeb/algorithms/graph/data/AdjacentList.kt

57 lines
2.0 KiB
Kotlin

/*
* MIT License
*
* Copyright (c) 2019 norangebit
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this software and associated documentation files (the "Software"), to deal
* in the Software without restriction, including without limitation the rights
* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
* copies of the Software, and to permit persons to whom the Software is
* furnished to do so, subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in all
* copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
* SOFTWARE.
*
*/
package it.norangeb.algorithms.graph.data
import java.util.TreeMap
import kotlin.math.max
class AdjacentList : GraphData {
private val graph = TreeMap<Int, MutableList<Int>>()
private var edgeNumber = 0
private var maxVertexId = 0
override fun addEdge(firstVertex: Int, secondVertex: Int) {
graph.computeIfAbsent(firstVertex) { mutableListOf() }
graph[firstVertex]?.add(secondVertex)
computeMaxVertexId(firstVertex, secondVertex)
edgeNumber++
}
override fun adjacent(vertex: Int): Collection<Int> {
return graph[vertex] ?: listOf()
}
override fun vertexNumber(): Int = maxVertexId + 1
override fun edgeNumber(): Int = edgeNumber
private fun computeMaxVertexId(firstVertex: Int, secondVertex: Int) {
val max = max(firstVertex, secondVertex)
maxVertexId = max(max, maxVertexId)
}
}