java - 使用递归统计嵌套列表中奇数长度或偶数长度的列表数量

Question

如何在 Java 中编写一个递归方法，它接受一个嵌套列表并计算奇数长度列表的数量和偶数长度列表的数量？到目前为止，我只得到了这个:

public class MyRekursion {
    // [number of odd-lengthed lists, number of even-lengthed lists]
    public static int[] countOddEven(List<Object> nestedList) {
        int odd = 0;
        int even = 0;
        for (Object obj : nestedList){
            if (obj instanceof List){
                // ???
            }
        }

        return new int[] { odd, even };
    }
}

Answer 1

public class MyRecursion {
    public static int[] countOddEven(List nestedList) {
        int odd = 0;
        int even = 0;

        for (Object obj : nestedList) {
            if (obj instanceof List) {
                int[] res = countOddEven((List)obj);
                odd += res[0];
                even += res[1];
            }
        }

        if (nestedList.size() % 2 == 1) {
            ++odd;
        } else {
            ++even;
        }

        return new int[] { odd, even };
    }
}