Data commit

Task/Equilibrium-index/Scala/equilibrium-index.scala

@@ -0,0 +1,8 @@
+ def getEquilibriumIndex(A: Array[Int]): Int = {
+      val bigA: Array[BigInt] = A.map(BigInt(_))
+      val partialSums: Array[BigInt] = bigA.scanLeft(BigInt(0))(_+_).tail
+      def lSum(i: Int): BigInt = if (i == 0) 0 else partialSums(i - 1)
+      def rSum(i: Int): BigInt = partialSums.last - partialSums(i)
+      def isRandLSumEqual(i: Int): Boolean = lSum(i) == rSum(i)
+      (0 until partialSums.length).find(isRandLSumEqual).getOrElse(-1)
+    }