03 & 04 exercises (#96)

03_recursion/kotlin/01_countdown.kt

@@ -0,0 +1,11 @@
+private fun countdown(i: Int) {
+    println(i)
+    when {
+        // base case
+        i <= 0 -> return
+        // recursive case
+        else -> countdown(i - 1)
+    }
+}
+
+fun main(args: Array<String>) = countdown(5)

03_recursion/kotlin/02_greet.kt

@@ -0,0 +1,12 @@
+private fun greet2(name: String) = println("how are you, $name?")
+
+private fun bye() = println("ok bye!")
+
+private fun greet(name: String) {
+    println("hello, $name!")
+    greet2(name)
+    println("getting ready to say bye...")
+    bye()
+}
+
+fun main(args: Array<String>) = greet("adit")

03_recursion/kotlin/03_factorial.kt

@@ -0,0 +1,6 @@
+private fun fact(x: Int): Int = when (x) {
+    1 -> 1
+    else -> x * fact(x - 1)
+}
+
+fun main(args: Array<String>) = println(fact(5))