CountTripletsSolution.kt

// Complete the countTriplets function below.
fun countTriplets(arr: Array<Long>, r: Long): Long {
    var befMap = HashMap<Long, Int>()
    var aftMap = HashMap<Long, Int>()
    
    for(num in arr) {
        if(aftMap.containsKey(num)) aftMap[num] = aftMap[num]!! + 1
        else aftMap[num] = 1
    }
    
    var count = 0L
    for(num in arr) {
        if (aftMap.containsKey(num)) aftMap[num] = aftMap[num]!! - 1
        if (num % r == 0L && befMap.containsKey(num/r) &&  aftMap.containsKey(num*r) ) {
            count += befMap[num/r]!! * aftMap[num*r]!!
        }
        if (befMap.containsKey(num)) befMap[num] = befMap[num]!! + 1
        else befMap[num] = 1
    }
    return count

}