unordered dictionaries

- add interface of dictionaries

src/main/kotlin/it/norangeb/algorithms/datastructures/dictionary/Dictionaries.kt

@@ -0,0 +1,44 @@
+/*
+ * 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.Option
+
+interface Dictionary<K, V> {
+    operator fun get(key: K): Option<V>
+    operator fun set(key: K, value: V)
+    fun delete(key: K)
+    fun contains(key: K): Boolean
+    fun isEmpty(): Boolean
+    fun size(): Int
+}
+
+interface OrderedDictionary<K : Comparable<K>, V> : Dictionary<K, V> {
+    fun max(): K
+    fun min(): K
+    fun floor(key: K): K
+    fun ceiling(key: K): K
+}

src/main/kotlin/it/norangeb/algorithms/datastructures/dictionary/Map.kt

@@ -0,0 +1,76 @@
+/*
+ * 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.getOrElse
+import arrow.core.toOption
+
+class Map<K, V> : Dictionary<K, V> {
+    private var size = 0
+    private var head: Option<Node<K, V>> = None
+
+    override fun get(key: K): Option<V> = head.flatMap { node ->
+        node.find { elem.first == key }
+            .map { it.elem.second }
+    }
+
+    override fun set(key: K, value: V) = head
+        .flatMap { it.find { elem.first == key } }
+        .fold(
+            {
+                size++
+                val node = Node(Pair(key, value), head)
+                head = node.toOption()
+            },
+            { it.elem = Pair(key, value) }
+        )
+
+    override fun delete(key: K) {
+        head.flatMap {
+            it.find { next.map { it.elem.first == key }.getOrElse { false } }
+        }.map {
+            size--
+            it.next = it.next.flatMap { it.next }
+        }
+    }
+
+    override fun contains(key: K): Boolean = get(key) != None
+
+    override fun isEmpty(): Boolean = size == 0
+
+    override fun size(): Int = size
+
+    data class Node<K, V>(var elem: Pair<K, V>, var next: Option<Node<K, V>>) {
+        fun find(
+            predicate: Node<K, V>.() -> Boolean
+        ): Option<Node<K, V>> = when {
+            predicate(this) -> this.toOption()
+            else -> next.flatMap { it.find(predicate) }
+        }
+    }
+}

src/test/kotlin/it/norangeb/algorithms/datastructures/dictionary/MapTest.kt

@@ -0,0 +1,70 @@
+/*
+ * 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.junit.Before
+import org.junit.Test
+
+class MapTest {
+    lateinit var map: Dictionary<String, Int>
+
+    @Before
+    fun init() {
+        map = Map()
+    }
+
+    @Test
+    fun testMap() {
+        map.size() `should be equal to` 0
+        map.contains("TRE") `should be` false
+
+        map["TRE"] = 3
+        map["UNO"] = 0
+
+        map["DUE"] `should be` None
+        map["TRE"] should { this == Some(3) }
+
+        map["QUATTRO"] = 4
+        map["UNO"] = 1
+        map["DUE"] = 2
+
+        map.size() `should be equal to` 4
+        map.contains("DUE") `should be` true
+        map["UNO"] should { this == Some(1) }
+
+        map["CINQUE"] = 5
+        map.delete("DUE")
+        map.delete("SEI")
+
+        map.contains("DUE") `should be` false
+        map.size() `should be equal to` 4
+    }
+}