add basic implementation of BST
All checks were successful
continuous-integration/drone/push Build is passing

This commit is contained in:
Raffaele Mignone 2019-04-17 22:49:09 +02:00
parent 64010824f1
commit 95c2f8c02a
Signed by: norangebit
GPG Key ID: F5255658CB220573
3 changed files with 384 additions and 0 deletions

View File

@ -41,4 +41,8 @@ interface OrderedDictionary<K : Comparable<K>, V> : Dictionary<K, V> {
fun min(): Option<K>
fun floor(key: K): Option<K>
fun ceiling(key: K): Option<K>
fun select(pos: Int): Option<K>
fun <R> preOrder(transform: (K) -> R)
fun <R> inOrder(transform: (K) -> R)
fun <R> postOrder(transform: (K) -> R)
}

View File

@ -0,0 +1,200 @@
/*
* 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.datastructures.dictionary
import arrow.core.None
import arrow.core.Option
import arrow.core.Some
import arrow.core.toOption
class ImmutableBST<K : Comparable<K>, V> : OrderedDictionary<K, V> {
private var root: Option<Node<K, V>> = None
override fun get(key: K): Option<V> = get(root, key).map { it.value }
private fun get(node: Option<Node<K, V>>, key: K): Option<Node<K, V>> = node
.flatMap {
when {
it.key == key -> it.toOption()
key > it.key -> get(it.right, key)
else -> get(it.left, key)
}
}
override fun set(key: K, value: V) {
root = set(root, key, value)
}
private fun set(
node: Option<Node<K, V>>,
key: K, value: 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(it.right, key, value))
else -> it.clone(left = set(it.left, key, value))
}
}
).toOption()
override fun delete(key: K) {
root = delete(root, key)
}
private fun delete(
node: Option<Node<K, V>>,
key: K
): Option<Node<K, V>> = node.flatMap { deleteNode(it, key) }
private fun deleteNode(
node: Node<K, V>,
key: K
): Option<Node<K, V>> = when {
node.key == key -> when {
node.left is None && node.right is None -> None
node.left is None -> node.right
node.right is None -> node.left
else -> node.right.map { deleteNodeWithTwoChild(node, it) }
}
key > node.key -> node.clone(
right = delete(node.right, key)
).toOption()
else -> node.clone(left = delete(node.left, key)).toOption()
}
private fun deleteNodeWithTwoChild(
father: Node<K, V>,
rightChild: Node<K, V>
): Node<K, V> {
val replacement = down(rightChild) { left }
return replacement
.clone(
left = father.left,
right = delete(rightChild.toOption(), replacement.key)
)
}
override fun contains(key: K): Boolean = get(root, key) is Some
override fun isEmpty(): Boolean = root is None
override fun size(): Int = size(root)
private fun size(node: Option<Node<K, V>>) = node.fold(
{ 0 },
{ it.child + 1 }
)
override fun max(): Option<K> = root.map {
down(it) { right }.key
}
override fun min(): Option<K> = root.map {
down(it) { left }.key
}
private fun down(
node: Node<K, V>,
side: Node<K, V>.() -> Option<Node<K, V>>
): Node<K, V> = side(node)
.fold({ node }, { down(it, side) })
override fun select(pos: Int): Option<K> = select(root, pos)
private fun select(
node: Option<Node<K, V>>,
pos: Int
): Option<K> =
node.flatMap {
val leftChild = size(it.left)
when {
leftChild > pos -> select(it.left, pos)
leftChild < pos -> select(it.right, pos - leftChild - 1)
else -> it.key.toOption()
}
}
override fun floor(key: K): Option<K> {
TODO("not implemented") //To change body of created functions use File | Settings | File Templates.
}
override fun ceiling(key: K): Option<K> {
TODO("not implemented") //To change body of created functions use File | Settings | File Templates.
}
override fun <R> inOrder(transform: (K) -> R) = inOrder(root, transform)
private fun <R> inOrder(node: Option<Node<K, V>>, action: (K) -> R) {
node.map {
inOrder(it.left, action)
action(it.key)
inOrder(it.right, action)
}
}
override fun <R> postOrder(transform: (K) -> R) = postOrder(root, transform)
private fun <R> postOrder(node: Option<Node<K, V>>, action: (K) -> R) {
node.map {
postOrder(it.left, action)
postOrder(it.right, action)
action(it.key)
}
}
override fun <R> preOrder(transform: (K) -> R) = preOrder(root, transform)
private fun <R> preOrder(node: Option<Node<K, V>>, action: (K) -> R) {
node.map {
action(it.key)
preOrder(it.left, action)
preOrder(it.right, action)
}
}
data class Node<K : Comparable<K>, V>(
val key: K,
val value: V,
val left: Option<Node<K, V>> = None,
val right: Option<Node<K, V>> = None,
val child: Int = 0
) {
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<K, V> {
val leftChild = left.fold({ 0 }, { it.child + 1 })
val rightChild = right.fold({ 0 }, { it.child + 1 })
return Node(key, value, left, right, leftChild + rightChild)
}
}
}

View File

@ -0,0 +1,180 @@
/*
* 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.datastructures.dictionary
import arrow.core.None
import arrow.core.Some
import org.amshove.kluent.`should be equal to`
import org.amshove.kluent.`should be`
import org.amshove.kluent.should
import org.amshove.kluent.shouldEqual
import org.junit.jupiter.api.Test
class ImmutableBSTTest {
@Test
fun test() {
val orderedMap: OrderedDictionary<String, Int> = ImmutableBST()
orderedMap.isEmpty() `should be` true
orderedMap.size() `should be equal to` 0
orderedMap.contains("UNO") `should be` false
orderedMap.max() `should be` None
orderedMap.min() `should be` None
orderedMap["QUATTRO"] = 4
orderedMap["UNO"] = 0
orderedMap.contains("UNO") `should be` true
orderedMap["TRE"] = 3
orderedMap["UNO"] = 1
orderedMap.size() `should be equal to` 3
orderedMap["UNO"] should { this == Some(1) }
orderedMap["DUE"] = 2
orderedMap["DUE"] should { this == Some(2) }
orderedMap.max() should { this == Some("UNO") }
orderedMap.min() should { this == Some("DUE") }
}
@Test
fun testDelete() {
val orderedMap: OrderedDictionary<Int, String> = ImmutableBST()
orderedMap[7] = "sette"
orderedMap[2] = "due"
orderedMap[3] = "tre"
orderedMap[10] = "dieci"
orderedMap[1] = "uno"
orderedMap[8] = "otto"
orderedMap[13] = "tredici"
orderedMap[5] = "cinque"
orderedMap[11] = "undici"
orderedMap.size() `should be equal to` 9
// delete absent key
orderedMap.delete(0)
orderedMap.size() `should be equal to` 9
//delete node with no child
orderedMap.delete(1)
orderedMap.size() `should be equal to` 8
orderedMap.min() should { this == Some(2) }
//delete node with only right child
orderedMap.delete(2)
orderedMap.size() `should be equal to` 7
orderedMap.min() should { this == Some(3) }
//delete node with two child
orderedMap.delete(10)
orderedMap.size() `should be equal to` 6
orderedMap.delete(13)
//delete node with only left child
orderedMap.delete(11)
orderedMap.size() `should be equal to` 4
orderedMap.max() should { this == Some(8) }
}
@Test
fun testOrderedOperation() {
val orderedMap: OrderedDictionary<Int, Int> = ImmutableBST()
orderedMap.select(0) `should be` None
orderedMap[9] = 9
orderedMap[4] = 4
orderedMap[14] = 14
orderedMap.select(0) should { this == Some(4) }
orderedMap.select(1) should { this == Some(9) }
orderedMap.select(2) should { this == Some(14) }
orderedMap.select(3) `should be` None
orderedMap[13] = 13
orderedMap[15] = 15
orderedMap[3] = 3
orderedMap[5] = 5
orderedMap[2] = 2
orderedMap[6] = 6
orderedMap[12] = 12
orderedMap[16] = 16
orderedMap[1] = 1
orderedMap.select(0) shouldEqual orderedMap.min()
orderedMap.select(11) shouldEqual orderedMap.max()
orderedMap[0] = 0
orderedMap[11] = 11
orderedMap[10] = 10
orderedMap[17] = 17
orderedMap[18] = 18
orderedMap[7] = 7
orderedMap[8] = 8
orderedMap.select(-1) `should be` None
orderedMap.select(0) should { this == Some(0) }
orderedMap.select(1) should { this == Some(1) }
orderedMap.select(5) should { this == Some(5) }
orderedMap.select(8) should { this == Some(8) }
orderedMap.select(9) should { this == Some(9) }
orderedMap.select(10) should { this == Some(10) }
orderedMap.select(14) should { this == Some(14) }
orderedMap.select(17) should { this == Some(17) }
orderedMap.select(18) should { this == Some(18) }
orderedMap.select(19) `should be` None
println(orderedMap.select(19))
val orderList = ArrayList<Int>()
orderedMap.inOrder { orderList.add(it) }
orderList shouldEqual listOf(0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12,
13, 14, 15, 16, 17, 18)
val postOrderList = ArrayList<Int>()
orderedMap.postOrder { postOrderList.add(it) }
postOrderList shouldEqual listOf(0, 1, 2, 3, 8, 7, 6, 5, 4, 10, 11, 12, 13, 18, 17, 16, 15,
14, 9)
val preOrderList = ArrayList<Int>()
orderedMap.preOrder { preOrderList.add(it) }
preOrderList shouldEqual listOf(9, 4, 3, 2, 1, 0, 5, 6, 7, 8, 14, 13, 12, 11, 10, 15, 16,
17, 18)
}
}