Question

我创建了2个HashMaps，用于存储来自两个txt文件的字符串值。我能够成功打印两个地图中重复的值，但是，我无法确定每个值重复的次数。

以下是我的代码，用于识别重复值：

 // find if hashmaps contain duplicate values
    boolean val = wordsMap.keySet().containsAll(wordsMap1.keySet());

// create new entry for hashmap
for (Entry<String, Integer> str : wordsMap.entrySet()) {
System.out.println("================= " + str.getKey());


if(wordsMap1.containsKey(str.getKey())){
    System.out.println("Map2 Contains Map 1 Key");
   }


}

System.out.println("================= " + val);

有什么建议吗？谢谢

我正在考虑

的内容

Map.values().equals(Map1.values()){
 count++;

}

Answer 1

如果我理解正确，您希望找到两个地图对象共有的值。（根据需要添加null和/或其他检查）

public static int duplicateCount(Map<String, Integer> m1, Map<String, Integer> m2) {

    int count = 0;
    Collection<Integer> m1Values = m1.values();
    Collection<Integer> m2Values = m2.values();

    for (Integer i : m1Values) {
        if (m2Values.contains(i)) {
            count++;
        }

    }

    return count;
}

Answer 2

获取地图之间的重复键数量

public static int getDuplicateKeyCount(Map<?, ?> m1, Map<?, ?> m2) {
    Set<?> tempSet = new HashSet<>(m1.keySet());
    tempSet.retainAll(new ArrayList<>(m2.keySet()));
    return tempSet.size(); 
}

获取地图之间的重复值数量

public static int getDuplicateValueCount(Map<?, ?> m1, Map<?, ?> m2) {
    List<?> tempList = new ArrayList<>(m1.values());
    tempList.retainAll(m2.values());
    return tempList.size();     
}

获取包含m2的值的m1频率的地图

public static <K, V> Map<V, Integer> getValueFrequencyMap(Map<K, V> m1, Map<K, V> m2) {
    Map<V, Integer> freq = new HashMap<>();

    Collection<V> col = m2.values();

    for(V val : m1.values()) {
        freq.put(val, Collections.frequency(col, val));
    }

    return freq;
}

Answer 3

以下是根据我对您的疑问的理解编写的示例程序。它查找并显示重复键以及重复值及其重复频率。逻辑是：要查找频率，请将复制元素从 map1 和 map2 作为参数传递给 countFrequency（）方法，该方法在转弯将返回重复次数。

package com.rahul.stackoverflow;

import java.util.HashMap;
import java.util.Map;
import java.util.Map.Entry;

public class DuplicateValHashMap {

    public static void main(String[] args) {

        Map<String, Integer> map1 = new HashMap<String, Integer>();
        Map<String, Integer> map2 = new HashMap<String, Integer>();

        map1.put("A", 1);
        map1.put("B", 2);
        map1.put("C", 3);
        map1.put("D", 4);
        map1.put("E", 5);

        map2.put("A", 1);
        map2.put("F", 2);
        map2.put("G", 1);
        map2.put("H", 3);
        map2.put("B", 2);

        for(Entry<String, Integer> entrySet : map1.entrySet()){
            if(map2.containsKey(entrySet.getKey())){
                System.out.println("Map2 contains keys of map1.");
                System.out.println("Duplicate keys are : " + entrySet.getKey());
            }
            if(map2.containsValue(entrySet.getValue())){
                System.out.println("Map2 contains values of map1.");
                System.out.println("Duplicate values are : " + entrySet.getValue()+  
                        " which is repeated " + countFrequency(map2, entrySet.getValue())+ " times.");
            }
        }

    }

    public static int countFrequency(Map<String, Integer> map, Integer value){
        int count = 0;
        for(Entry<String, Integer> entrySet : map.entrySet()){
            if(value == entrySet.getValue()){
                count++;
            }
        }

        return count;

    }

}

确定两个Hashmaps中重复值的频率

3 个答案: