Merge pull request #16 from joybanerjee08/master

Karatsuba in Kotlin

Author: Bhrigu Kansra

multiplication/karatsuba.kt

@@ -0,0 +1,22 @@
+fun main(args:Array<String>) {
+    print(karatsuba(923, 1723))
+  }
+fun karatsuba(x:Int, y:Int):Int {
+    if ((x).toString().length == 1 || ((y).toString().length == 1))
+    {
+      return x * y
+    }
+    else
+    {
+      val n = Math.max((x).toString().length, (y).toString().length)
+      val z = n / 2
+      val a = x / Math.pow(10.0, z.toDouble()).toInt()
+      val b = x % Math.pow(10.0, z.toDouble()).toInt()
+      val c = y / Math.pow(10.0, z.toDouble()).toInt()
+      val d = y % Math.pow(10.0, z.toDouble()).toInt()
+      val ac = karatsuba(a, c)
+      val bd = karatsuba(b, d)
+      val adbc = karatsuba(a + b, c + d) - ac - bd
+      return ac * Math.pow(10.0, (2 * z).toDouble()).toInt() + (adbc * Math.pow(10.0, z.toDouble()).toInt()) + bd
+    }
+ }