如何有效地求HashMaps数组中多个HashMaps的平均值？

import java.util.HashMap;

public class HashMapsAverage {
    public static HashMap<String, Double> calculateAverage(HashMap<String, Double>[] hashMapArray) {
        HashMap<String, Double> averageHashMap = new HashMap<>();

        // 遍历HashMaps数组，累加值到对应的键上
        for (HashMap<String, Double> hashMap : hashMapArray) {
            for (String key : hashMap.keySet()) {
                double value = hashMap.get(key);
                averageHashMap.put(key, averageHashMap.getOrDefault(key, 0.0) + value);
            }
        }

        int hashMapArrayLength = hashMapArray.length;

        // 计算平均值
        for (String key : averageHashMap.keySet()) {
            double averageValue = averageHashMap.get(key) / hashMapArrayLength;
            averageHashMap.put(key, averageValue);
        }

        return averageHashMap;
    }

    public static void main(String[] args) {
        // 示例用法
        HashMap<String, Double>[] hashMapArray = new HashMap[3];
        hashMapArray[0] = new HashMap<>();
        hashMapArray[0].put("A", 10.0);
        hashMapArray[0].put("B", 20.0);
        hashMapArray[1] = new HashMap<>();
        hashMapArray[1].put("A", 30.0);
        hashMapArray[1].put("B", 40.0);
        hashMapArray[2] = new HashMap<>();
        hashMapArray[2].put("A", 50.0);
        hashMapArray[2].put("B", 60.0);

        HashMap<String, Double> averageHashMap = calculateAverage(hashMapArray);
        System.out.println(averageHashMap);
    }
}

{A=30.0, B=40.0}