将整数对象转换为基元类型时出现问题

Question

import java.util.*;
public class EnoughIsEnough {

    public static int[] deleteNth(int[] elements, int maxOccurrences) {
      ArrayList arrList = new ArrayList<>(Arrays.asList(elements));
    for (int i = 0; i < arrList.size(); i++) {
      int current = (int)arrList.get(i);
      int occurrences = 1;
      for (int j = i + 1; j < arrList.size(); j++) {
        if (arrList.get(j).equals(current) && occurrences >= maxOccurrences) {
          arrList.remove(j);
        } else if (arrList.get(j).equals(current)) {
          occurrences++;
        }
      }
    }
    int arr[] = new int[arrList.size()];
    for (int i = 0; i < arrList.size(); i++) {
      arr[i] = (int) arrList.get(i);
    }
    return arr;
    }

}

Answer 1

arrays.aslist(elements)并不像您想象的那样，它返回包含int[]数组的列表，而不是数组的元素。不能创建基元列表。如果要使用List，必须首先将int转换为integer。

您可以使用以下命令获取integer的列表

List<Integer> arrList = Arrays.stream(elements).boxed().collect(Collectors.toList());

但是，您的程序中仍然有一个错误，您将跳过数字。

for (int j = i + 1; j < arrList.size(); j++) {
  if (arrList.get(j).equals(current) && occurrences >= maxOccurrences) {
    arrList.remove(j); // This shortens the list causing us to skip the next element
    j--; // One hackish way is to go back one step

  } else if (arrList.get(j).equals(current)) {
    occurrences++;
  }
}

for (int j = arrList.size() - 1; j > i; j--) {
  if (arrList.get(j).equals(current) && occurrences >= maxOccurrences) {
    arrList.remove(j);
  } else if (arrList.get(j).equals(current)) {
    occurrences++;
  }
}