Ordered Set

Author: gazolla

OrderedSet/OrderedSet.kt

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+/**
+ * Created by gazollajunior on 08/04/16.
+ */
+
+class OrderedSet<T:Comparable<T>>(list:MutableList<T>){
+
+    var items: MutableList<T>  = list
+
+     fun insert(element:T) {
+        if (exists(element)) {
+           return
+        }
+        for (i in 0..this.items.count() - 1){
+            if (this.items[i] > element){
+                this.items.add(i, element)
+                return
+            }
+        }
+         this.items.add(element)
+    }
+
+    /**
+     * Use binarySearch algorithm to find the position for the new element in array
+     */
+
+    fun findElementPosition(element:T):Int?{
+        var rangeStart = 0
+        var rangeEnd = this.items.count()
+        while (rangeStart < rangeEnd) {
+            val midIndex = rangeStart + (rangeEnd - rangeStart)/2
+            if (this.items[midIndex] == element) {
+                return midIndex
+            } else if (this.items[midIndex] < element){
+                rangeStart = midIndex + 1
+            } else {
+                rangeEnd = midIndex
+            }
+        }
+        return null
+    }
+
+    override fun toString():String = this.items.toString()
+
+    fun isEmpty():Boolean = this.items.isEmpty()
+
+    fun exists(element:T):Boolean = findElementPosition(element) != null
+
+    fun count():Int = this.items.count()
+
+    fun remove(element:T) {
+        val position = findElementPosition(element)
+        if (position != null) {
+            this.items.removeAt(position)
+        }
+    }
+
+    fun removeAll() =  this.items.removeAll(this.items)
+
+    fun max():T? {
+        if (count() != 0) {
+            return this.items[count() - 1]
+        } else {
+            return null
+        }
+    }
+    fun min():T? {
+        if (count() != 0) {
+            return this.items[0]
+        } else {
+            return null
+        }
+    }
+}
+
+
+
+fun main(args: Array<String>) {
+
+
+    println("\nOriginal set:")
+    val names =  mutableListOf<String>("Demetrius")
+
+    var nameSet = OrderedSet<String>(names)
+    println(nameSet)
+
+
+    val n1 = "Adam"
+    println("\nAdding ${n1} to the list:")
+    nameSet.insert(n1)
+    println(nameSet)
+
+    val n2 = "Tim"
+    println("\nAdding ${n2} to the list:")
+    nameSet.insert(n2)
+    println(nameSet)
+
+    val n3 = "Zack"
+    println("\nAdding ${n3} to the list:")
+    nameSet.insert(n3)
+    println(nameSet)
+
+    val n4 = "Zack"
+    println("\nTry Add ${n4} again to the list:")
+    nameSet.insert(n4)
+    println(nameSet)
+	
+	nameSet.remove(n2)
+	println("\nRemoving ${n2} from the list:")
+	println(nameSet)
+
+	nameSet.remove(n4)
+	println("\nRemoving ${n4} from the list:")
+	println(nameSet)
+
+	nameSet.remove(n1)
+	println("\nRemoving ${n1} from the list:")
+	println(nameSet)
+
+}

OrderedSet/README.markdown

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+# Ordered Set
+
+An ordered set is a common data structure that supports O(log N) lookups, insertions and removals. Ordered set is also sometimes used as an alternative to a hash map, for example in STL’s map.
+
+The implementation is quite basic:
+
+```kotlin
+class OrderedSet<T:Comparable<T>>(list:MutableList<T>){
+
+    var items: MutableList<T>  = list
+
+     fun insert(element:T) {
+        if (exists(element)) {
+           return
+        }
+        for (i in 0..this.items.count() - 1){
+            if (this.items[i] > element){
+                this.items.add(i, element)
+                return
+            }
+        }
+         this.items.add(element)
+    }
+
+    /**
+     * Use binarySearch algorithm to find the position for the new element in array
+     */
+
+    fun findElementPosition(element:T):Int?{
+        var rangeStart = 0
+        var rangeEnd = this.items.count()
+        while (rangeStart < rangeEnd) {
+            val midIndex = rangeStart + (rangeEnd - rangeStart)/2
+            if (this.items[midIndex] == element) {
+                return midIndex
+            } else if (this.items[midIndex] < element){
+                rangeStart = midIndex + 1
+            } else {
+                rangeEnd = midIndex
+            }
+        }
+        return null
+    }
+
+    override fun toString():String = this.items.toString()
+
+    fun isEmpty():Boolean = this.items.isEmpty()
+
+    fun exists(element:T):Boolean = findElementPosition(element) != null
+
+    fun count():Int = this.items.count()
+
+    fun remove(element:T) {
+        val position = findElementPosition(element)
+        if (position != null) {
+            this.items.removeAt(position)
+        }
+    }
+
+    fun removeAll() =  this.items.removeAll(this.items)
+
+    fun max():T? {
+        if (count() != 0) {
+            return this.items[count() - 1]
+        } else {
+            return null
+        }
+    }
+    fun min():T? {
+        if (count() != 0) {
+            return this.items[0]
+        } else {
+            return null
+        }
+    }
+}
+
+```