valid parentheses solution

Author: yhkee0404

valid-parentheses/yhkee0404.scala

@@ -0,0 +1,26 @@
+import scala.collection.mutable.ArrayBuffer
+
+object Solution {
+    var encoder = "(){}[]".zipWithIndex
+            .toMap
+    def isValid(s: String): Boolean = {
+        val arr = ArrayBuffer[Int]()
+        s.forall { c =>
+                    val x = encoder(c)
+                    if ((x & 1) == 0) {
+                        arr += x
+                        true
+                    } else {
+                        arr.lastOption match {
+                            case Some(y) => {
+                                if (y == x - 1) {
+                                    arr.dropRightInPlace (1)
+                                    true
+                                } else false
+                            }
+                            case None => false
+                        }
+                    }
+                } && arr.isEmpty
+    }
+}