JAVA求字符串数组交集、并集和差集

谁借莪１个温暖的怀抱￠ 2023-10-17 14:00 48阅读 0赞

package string;   
      
    import java.util.HashMap;   
    import java.util.HashSet;   
    import java.util.LinkedList;   
    import java.util.Map;   
    import java.util.Map.Entry;   
    import java.util.Set;   
      
    public class StringArray {   
        public static void main(String[] args) {   
            //测试union   
            String[] arr1 = {"abc", "df", "abc"};   
            String[] arr2 = {"abc", "cc", "df", "d", "abc"};   
            String[] result_union = union(arr1, arr2);   
            System.out.println("求并集的结果如下：");   
            for (String str : result_union) {   
                System.out.println(str);   
            }   
            System.out.println("---------------------可爱的分割线------------------------");   
      
            //测试insect   
            String[] result_insect = intersect(arr1, arr2);   
            System.out.println("求交集的结果如下：");   
            for (String str : result_insect) {   
                System.out.println(str);   
            }   
      
             System.out.println("---------------------疯狂的分割线------------------------");   
              //测试minus   
            String[] result_minus = minus(arr1, arr2);   
            System.out.println("求差集的结果如下：");   
            for (String str : result_minus) {   
                System.out.println(str);   
            }   
        }   
      
        //求两个字符串数组的并集，利用set的元素唯一性   
        public static String[] union(String[] arr1, String[] arr2) {   
            Set<String> set = new HashSet<String>();   
            for (String str : arr1) {   
                set.add(str);   
            }   
            for (String str : arr2) {   
                set.add(str);   
            }   
            String[] result = {};   
            return set.toArray(result);   
        }   
      
        //求两个数组的交集   
        public static String[] intersect(String[] arr1, String[] arr2) {   
            Map<String, Boolean> map = new HashMap<String, Boolean>();   
            LinkedList<String> list = new LinkedList<String>();   
            for (String str : arr1) {   
                if (!map.containsKey(str)) {   
                    map.put(str, Boolean.FALSE);   
                }   
            }   
            for (String str : arr2) {   
                if (map.containsKey(str)) {   
                    map.put(str, Boolean.TRUE);   
                }   
            }   
      
            for (Entry<String, Boolean> e : map.entrySet()) {   
                if (e.getValue().equals(Boolean.TRUE)) {   
                    list.add(e.getKey());   
                }   
            }   
      
            String[] result = {};   
            return list.toArray(result);   
        }   
      
        //求两个数组的差集   
        public static String[] minus(String[] arr1, String[] arr2) {   
            LinkedList<String> list = new LinkedList<String>();   
            LinkedList<String> history = new LinkedList<String>();   
            String[] longerArr = arr1;   
            String[] shorterArr = arr2;   
            //找出较长的数组来减较短的数组   
            if (arr1.length > arr2.length) {   
                longerArr = arr2;   
                shorterArr = arr1;   
            }   
            for (String str : longerArr) {   
                if (!list.contains(str)) {   
                    list.add(str);   
                }   
            }   
            for (String str : shorterArr) {   
                if (list.contains(str)) {   
                    history.add(str);   
                    list.remove(str);   
                } else {   
                    if (!history.contains(str)) {   
                        list.add(str);   
                    }   
                }   
            }   
      
            String[] result = {};   
            return list.toArray(result);   
        }   
    }