lm-tecniche-di-programmazione/src/main/kotlin/it/norangeb/algorithms/exam/MaxWidthTree.kt

111 lines
3.2 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.exam
import arrow.core.None
import arrow.core.Option
import arrow.core.toOption
import kotlin.math.abs
class MaxWidthTree<K : Comparable<K>, V> {
private var root: Option<Node<K, V>> = None
operator fun set(key: K, value: V) {
root = set(key, value, root)
}
private fun set(
key: K,
value: V,
node: Option<Node<K, V>>
): Option<Node<K, V>> = node.fold(
{ Node(key, value) },
{
when {
key == it.key -> it.clone(value = value)
key > it.key -> it.clone(right = set(key, value, it.right))
else -> it.clone(left = set(key, value, it.left))
}
}).toOption()
operator fun get(key: K): Option<V> = get(key, root).map { it.value }
private fun get(
key: K,
node: Option<Node<K, V>>
): Option<Node<K, V>> = node.flatMap {
when {
key == it.key -> node
key > it.key -> get(key, it.right)
else -> get(key, it.left)
}
}
fun getMaxWidth(): Int {
val count = Array(100) { 0 }
val level = 0
computeWidth(root, count, level)
return count[getMax(count)]
}
private fun computeWidth(
node: Option<Node<K, V>>,
count: Array<Int>,
level: Int
) {
node.map {
count[level]++
computeWidth(it.left, count, level + 1)
computeWidth(it.right, count, level + 1)
}
}
private fun getMax(count: Array<Int>): Int {
var maxIndex = 0
count.forEachIndexed { index, i ->
if (i > count[maxIndex])
maxIndex = index
}
return maxIndex
}
private data class Node<K, V>(
val key: K,
val value: V,
val left: Option<Node<K, V>> = None,
val right: Option<Node<K, V>> = None
) {
fun clone(
key: K = this.key,
value: V = this.value,
left: Option<Node<K, V>> = this.left,
right: Option<Node<K, V>> = this.right
) = Node(key, value, left, right)
}
}