查找一个数组是否包含另一个数组中的所有元素 [英] Finding if an array contains all elements in another array

问题描述

我正在尝试遍历 2 个数组，外部数组比另一个数组长.它将遍历第一个数组，如果第二个数组不包含该 int，它将返回 false.但我无法弄清楚如何解决这个问题.这是我目前所拥有的:

I am trying to loop through 2 arrays, the outer array is longer then the other. It will loop through the first and if the 2nd array does not contain that int it will return a false. But I cannot figure out how to go about this. This is what I have so far:

public boolean linearIn(int[] outer, int[] inner) {
  for (int i = 0; i < outer.length; i++) {
    if (!inner.contains(outer[i])) {
      return false;
    }
  }

  return true;
}

运行时出现此错误:

Cannot invoke contains(int) on the array type int[]

我想知道是否可以在不使用嵌套循环(如上)的情况下完成.我知道我做错了什么，如果有人可以帮助解决这个问题，那就太好了.此外，我不确定要在 int[] 的 java 文档中查找哪个类.

I am wondering if it can be done without using a nested loop (like above). I know I'm doing something wrong and if anyone could help on the matter it would be great. Also I wasn't sure what class to look for in the java doc for the int[].

推荐答案

您可以检查数组中较大的 outer 是否包含较小数组中的每个元素，即 inner:

You could check that the larger of the arrays outer contains every element in the smaller one, i.e. inner:

public static boolean linearIn(Integer[] outer, Integer[] inner) {

   return Arrays.asList(outer).containsAll(Arrays.asList(inner));
}

注意:此方法需要 Integer 类型才能工作.如果使用原语，则 Arrays.asList 将返回一个 List，其中包含一个 int[] 类型的元素.在这种情况下，调用 containsAll 不会检查数组的实际内容，而是比较原始 int 数组 Object 引用.

Note: Integer types are required for this approach to work. If primitives are used, then Arrays.asList will return a List containing a single element of type int[]. In that case, invoking containsAll will not check the actual content of the arrays but rather compare the primitive int array Object references.

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