Added Heap Sort, Selection sort, and Bubble sort in Kotlin

Kotlin/BubbleSort.kt

@@ -0,0 +1,32 @@
+import java.util.stream.Stream
+import kotlin.random.Random
+
+fun bubbleSort(array: IntArray) {
+    for (pass in 0 until array.size - 1) {
+        for (currentPosition in 0 until array.size - pass - 1) {
+            if (array[currentPosition] > array[currentPosition + 1]) {
+                val temp = array[currentPosition]
+                array[currentPosition] = array[currentPosition + 1]
+                array[currentPosition + 1] = temp
+            }
+        }
+    }
+}
+
+fun main() {
+    //just generate data
+    val random = Random
+    val size = 10L
+    val maxElement = 100
+    val array: IntArray = Stream.generate { random.nextInt(maxElement) }.limit(size).toArray()
+            .map { it.toString().toInt() }
+            .toIntArray()
+
+    println("Array element before bubble sort : ")
+    array.iterator().forEach { print("$it ") }
+
+    bubbleSort(array)
+
+    println("\nArray element after bubble sort : ")
+    array.iterator().forEach { print("$it ") }
+}

Kotlin/HeapSort.kt

@@ -0,0 +1,56 @@
+
+import java.util.stream.Stream
+import kotlin.random.Random
+
+
+private fun buildMaxHeap(array: IntArray) {
+    for (i in array.size / 2 - 1 downTo 0) {
+        maxHeap(array, i)
+    }
+}
+
+private fun maxHeap(array: IntArray, rootIndex: Int, heapSize: Int = array.size - 1) {
+    val leftChildIndex = 2 * rootIndex + 1
+    val rightChildIndex = 2 * rootIndex + 2
+    var largestElementIndex = rootIndex
+
+    if (leftChildIndex <= heapSize && array[leftChildIndex] > array[rootIndex]) {
+        largestElementIndex = leftChildIndex
+    }
+
+    if (rightChildIndex <= heapSize && array[rightChildIndex] > array[largestElementIndex]) {
+        largestElementIndex = rightChildIndex
+    }
+
+    if (largestElementIndex != rootIndex) {
+        val temp = array[rootIndex]
+        array[rootIndex] = array[largestElementIndex]
+        array[largestElementIndex] = temp
+        maxHeap(array, largestElementIndex, heapSize)
+    }
+}
+
+fun main() {
+    //just generate data
+    val r = Random
+    val size = 30L
+    val maxElement = 500
+    val array: IntArray = Stream.generate { r.nextInt(maxElement) }.limit(size).toArray()
+            .map { it.toString().toInt() }
+            .toIntArray()
+
+    buildMaxHeap(array)
+
+    println("Array element before heap sort : ")
+    array.iterator().forEach { print("$it ") }
+
+    for (i in array.size - 1 downTo 1) {
+        val temp = array[0]
+        array[0] = array[i]
+        array[i] = temp
+        maxHeap(array, 0, i - 1)
+    }
+
+    println("\nArray element after heap sort : ")
+    array.iterator().forEach { print("$it ") }
+}

Kotlin/SelectionSort.kt

@@ -0,0 +1,41 @@
+import java.util.stream.Stream
+import kotlin.random.Random
+
+fun selectionSort(array: IntArray) {
+
+    val size = array.size
+    var temp : Int
+
+    for(i in size-1 downTo 0){
+        var max = i
+
+        for(j in 0 until i){
+            if(array[j] > array[max]) max=j
+        }
+
+        if(i!=max){
+            temp = array[i]
+            array[i] = array[max]
+            array[max] = temp
+        }
+    }
+
+}
+
+fun main() {
+    //just generate data
+    val r = Random
+    val size = 10L
+    val maxElement = 100
+    val array: IntArray = Stream.generate { r.nextInt(maxElement) }.limit(size).toArray()
+            .map { it.toString().toInt() }
+            .toIntArray()
+
+    println("Array element before selection sort : ")
+    array.iterator().forEach { print("$it ") }
+
+    selectionSort(array)
+
+    println("\nArray element after selection sort : ")
+    array.iterator().forEach { print("$it ") }
+}