September 2017 Update

Task/Nth-root/Kotlin/nth-root.kotlin

@@ -0,0 +1,21 @@
+// version 1.0.6
+
+fun nthRoot(x: Double, n: Int): Double {
+    if (n < 2) throw IllegalArgumentException("n must be more than 1")
+    if (x <= 0.0) throw IllegalArgumentException("x must be positive")
+    val np = n - 1
+    fun iter(g: Double) = (np * g + x / Math.pow(g, np.toDouble())) / n
+    var g1 = x
+    var g2 = iter(g1)
+    while (g1 != g2) {
+        g1 = iter(g1)
+        g2 = iter(iter(g2))
+    }
+    return g1
+}
+
+fun main(args: Array<String>) {
+   val numbers = arrayOf(1728.0 to 3, 1024.0 to 10, 2.0 to 2)
+   for (number in numbers)
+       println("${number.first} ^ 1/${number.second}\t = ${nthRoot(number.first, number.second)}")
+}