求出具有相同第一个元素的配对的平均值。kotlin

fun calculateAverage(pairs: List<Pair<Int, Int>>): List<Pair<Int, Double>> {
    val hashMap = HashMap<Int, Pair<Int, Double>>()
    
    for (pair in pairs) {
        val firstValue = pair.first
        val secondValue = pair.second
        
        if (hashMap.containsKey(firstValue)) {
            val existingPair = hashMap[firstValue]!!
            val newSum = existingPair.second + secondValue
            val newCount = existingPair.first + 1
            hashMap[firstValue] = Pair(newCount, newSum)
        } else {
            hashMap[firstValue] = Pair(1, secondValue.toDouble())
        }
    }
    
    val result = ArrayList<Pair<Int, Double>>()
    
    for (entry in hashMap.entries) {
        val key = entry.key
        val count = entry.value.first
        val sum = entry.value.second
        val average = sum / count
        result.add(Pair(key, average))
    }
    
    return result
}