java - 查找两个数组中相同的重数

Question

我需要有关 SameElements() 方法的帮助。我需要以随机顺序获取两个用户输入的数组，并查看它们是否具有相同的多重性。

我知道如果它们的长度不同，那么它们就不会有相同的元素。但这就是我所得到的。我的 sameSet() 方法中的代码可以为此修改吗？或者我需要做一些完全不同的事情吗？

 ` /**
 * checks whether two arrays have the same elements in some order, with
 * the same multiplicities. For example, 1 4 9 16 9 7 4 9 11 and 11 1 4 9 16
 * 9 7 4 9 would be considered identical
 *
 */

 public static boolean sameElements(Integer a[], int sizeA, Integer b[], int sizeB) {
    if (a.length != b.length) {
        return false; 
    }
      // need help on this, length portion is all I have.
 }


 /**
 * check whether two arrays have the same elements in some order, ignoring
 * duplicates. For example, the two arrays 1 4 9 16 9 7 4 9 11 and 11 11 7 9
 * 16 4 1 would be considered identical.
 */

public static boolean sameSet(Integer[] a, int sizeA, Integer[] b, int sizeB) {

    HashSet<Integer> set1 = new HashSet<Integer>(Arrays.asList(a)); // Put arrays a & b into hashset */
    HashSet<Integer> set2 = new HashSet<Integer>(Arrays.asList(b));

    //Compares the sets to see if they have the same elements 

    if (set1.equals(set2)) {
        System.out.println("The elements of the arrays A and B form the same set.");
    } else {
        System.out.println("The elements of the arrays A and B do not1 form the same set.");
    }
    return set1.equals(set2);

}

public static void main() {
    final int LENGTH = 30;
    int sizeA = 0;
    int sizeB = 0;
    Integer a[] = new Integer[LENGTH];
    Integer b[] = new Integer[LENGTH];
    Scanner input = new Scanner(System.in);
    Scanner in = new Scanner(System.in);

        System.out.println("Please fill up values for array a, Q to quit: "); //Gather user input for array A
        while (input.hasNextInt() && sizeA < a.length) {
            a[sizeA] = input.nextInt();
            sizeA++;
        }
        System.out.println("# of values in array A:" + sizeA + "\n");

        System.out.println("Please fill up values for array b, type in Q to quit: "); //Gather user input for array B
        while (in.hasNextInt() && sizeB < b.length) {
            b[sizeB] = in.nextInt();
            sizeB++;
        }
        System.out.println("# of values in array B:" + sizeB);
        //Take the user input and test it through each method
        equals(a, sizeA, b, sizeB); 
        sameSet(a, sizeA, b, sizeB);
        sameElements(a, sizeA, b, sizeB);


    }
}

Answer 1

您可以使用 Set 的 containsAll 方法轻松实现它。我写了下面的程序。请检查是否对您有帮助。

    Set a = new HashSet<Integer>();
    Set b = new HashSet<Integer>();
    a.add(1);
    a.add(2);
    a.add(3);

    b.add(3);
    b.add(2);
    b.add(1);
    if(a.containsAll(b) && b.containsAll(a))
    {
        System.out.println("Same elements in both");            
    }
    else
    {
        System.out.println("Not same elements in both");
    }