# create a link list example

build.gradle

@@ -35,5 +35,6 @@ repositories {
 
 dependencies {
     testCompile 'junit:junit:4.12'
+    testCompile 'com.carrotsearch:junit-benchmarks:0.7.2'
     compile "org.jetbrains.kotlin:kotlin-stdlib:$kotlin_version"
 }

src/main/io/uuddlrlrba/ktalgs/datastructures/LinkedList.kt

@@ -0,0 +1,49 @@
+/*
+ * Copyright (c) 2017 Kotlin Algorithm Club
+ *
+ * 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 io.uuddlrlrba.ktalgs.datastructures
+
+enum class  LinkedType {
+    END, NODE
+}
+
+class LinkedListKotlin<T>: Cloneable{
+
+    private data class Node<T>(val item: T? = null,  val tail: LinkedListKotlin<T>? = null)
+
+    private var type: LinkedType = LinkedType.END
+    private var node: Node<T>? = null
+
+    fun push(item: T) {
+        val tail = this.clone() as? LinkedListKotlin<T>
+        this.node = Node(item, tail)
+        type = LinkedType.NODE
+    }
+
+    fun pop(): T? {
+        val returnItem =  this.node?.copy()?.item
+        val nextNode = this.node?.tail?.node
+        this.node = Node(nextNode?.item, nextNode?.tail)
+        return returnItem
+    }
+}
+

src/test/io/uuddlrlrba/ktalgs/datastructures/LinkedListTest.kt

@@ -0,0 +1,70 @@
+/*
+ * Copyright (c) 2017 Kotlin Algorithm Club
+ *
+ * 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 io.uuddlrlrba.ktalgs.datastructures
+
+import com.carrotsearch.junitbenchmarks.BenchmarkOptions
+import com.carrotsearch.junitbenchmarks.BenchmarkRule
+import org.junit.Before
+import org.junit.Rule
+import org.junit.Test
+
+
+class LinkedListTest {
+
+    private lateinit var linkedList: LinkedListKotlin<Int>
+
+    @Before
+    fun init() {
+        linkedList = LinkedListKotlin()
+    }
+
+    @get:Rule
+    public val benchmarkRule: BenchmarkRule = BenchmarkRule()
+
+    @Test
+    fun emptyTest() {
+        val test2 = linkedList.pop()
+    }
+
+
+    @Test
+    fun pushAndPopTest() {
+        val linkedList: LinkedListKotlin<Int> = LinkedListKotlin()
+        linkedList.push(1)
+        linkedList.push(2)
+        linkedList.push(3)
+        val test1 = linkedList.pop()
+        val test2 = linkedList.pop()
+    }
+
+    @Test
+    @BenchmarkOptions(concurrency = 1, warmupRounds = 0, benchmarkRounds = 1)
+    fun benchmarkSomeWork()  {
+        for (i in 0..1000000) {
+            linkedList.push(i)
+        }
+        for (i in 0..1000000) {
+            linkedList.pop()
+        }
+    }
+}