Create Problem4.scala

scala/Problem4.scala

@@ -0,0 +1,23 @@
+object Main extends App {
+
+  def time[R](block: => R): R = {
+    val t0 = System.nanoTime()
+    val result = block    // call-by-name
+    val t1 = System.nanoTime()
+    println("Elapsed time: " + (t1 - t0)*0.000000001 + "s")
+    result
+  }
+
+//O(n^2)
+  time {
+    def palindrome (value: String) =
+      value.substring(0, value.length/2) == value.substring(value.length/2).reverse
+    def answer = (for (a <- 100 until 999 ; b <- 100 until 999
+                       if palindrome(a * b toString))
+      yield a*b).max
+
+    print(answer)
+  }
+
+
+}