Solution.scala

import scala.collection.mutable

object Solution {
    def twoSum(nums: Array[Int], target: Int): Array[Int] = {
        val d = mutable.Map[Int, Int]()
        var ans: Array[Int] = Array()
        for (i <- nums.indices if ans.isEmpty) {
            val x = nums(i)
            val y = target - x
            if (d.contains(y)) {
                ans = Array(d(y), i)
            } else {
                d(x) = i
            }
        }
        ans
    }
}