Data commit

Task/Stack/Kotlin/stack.kotlin

@@ -0,0 +1,45 @@
+// version 1.1.2
+
+class Stack<E> {
+    private val data = mutableListOf<E>()
+
+    val size get() = data.size
+
+    val empty get() = size == 0
+
+    fun push(element: E) = data.add(element)
+
+    fun pop(): E {
+        if (empty) throw RuntimeException("Can't pop elements from an empty stack")
+        return data.removeAt(data.lastIndex)
+    }
+
+    val top: E
+        get() {
+            if (empty) throw RuntimeException("Empty stack can't have a top element")
+            return data.last()
+        }
+
+    fun clear() = data.clear()
+
+    override fun toString() = data.toString()
+}
+
+fun main(args: Array<String>) {
+    val s = Stack<Int>()
+    (1..5).forEach { s.push(it) }
+    println(s)
+    println("Size of stack = ${s.size}")
+    print("Popping: ")
+    (1..3).forEach { print("${s.pop()} ") }
+    println("\nRemaining on stack: $s")
+    println("Top element is now ${s.top}")
+    s.clear()
+    println("After clearing, stack is ${if(s.empty) "empty" else "not empty"}")
+    try {
+        s.pop()
+    }
+    catch (e: Exception) {
+        println(e.message)
+    }
+}