add exercise kmin

- update kluent

buildSrc/src/main/java/Config.kt

@@ -26,7 +26,7 @@
 object Config {
     object Versions {
         val arrow = "0.8.2"
-        val kluent = "1.48"
+        val kluent = "1.49"
         val koin = "1.0.2"
         val junit = "5.4.2"
         val spek = "2.0.1"

src/main/kotlin/it/norangeb/algorithms/exercises/KMin.kt

@@ -0,0 +1,51 @@
+/*
+ * 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.exercises
+
+import arrow.core.None
+import arrow.core.Option
+import it.norangeb.algorithms.datastructures.queue.priority.BinaryHeap
+
+class KMin<T : Comparable<T>>(private val k: Int) {
+    private val heap = BinaryHeap.createMaxPriorityQueue<T>()
+
+    fun insert(elem: T): Option<T> {
+        heap.peek().fold(
+            { heap.insert(elem) },
+            {
+                if (elem < it || heap.size() < k)
+                    heap.insert(elem)
+            })
+
+        if (heap.size() > k)
+            heap.pop()
+
+        if (heap.size() < k)
+            return None
+
+        return heap.peek()
+    }
+}

src/test/kotlin/it/norangeb/algorithms/exercises/KMinTest.kt

@@ -0,0 +1,56 @@
+/*
+ * 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.exercises
+
+import arrow.core.None
+import arrow.core.Some
+import org.amshove.kluent.`should be`
+import org.amshove.kluent.shouldEqual
+import org.junit.jupiter.api.Test
+
+class KMinTest {
+
+    @Test
+    fun test() {
+        val input = listOf(15, 17, 9, 12, 22, 4, 73, 87, 12, 5)
+
+        val kmin = KMin<Int>(3)
+        val result = input.map { kmin.insert(it) }
+
+        result shouldEqual listOf(
+            None,
+            None,
+            Some(17),
+            Some(15),
+            Some(15),
+            Some(12),
+            Some(12),
+            Some(12),
+            Some(12),
+            Some(9)
+        )
+    }
+}