统计定界子数组的数目

/*
 * 思路：
 * 使用Java Stream处理定界子数组问题。尽管Stream API不太适合处理双指针问题，但我们仍然可以通过迭代和过滤来实现。
 */

import java.util.stream.IntStream;

public class Solution {
    public long countSubarrays(int[] nums, int minK, int maxK) {
        long[] result = {0};
        int[] minIndex = {-1};
        int[] maxIndex = {-1};
        int[] left = {0};

        IntStream.range(0, nums.length).forEach(right -> {
            if (nums[right] < minK || nums[right] > maxK) {
                left[0] = right + 1;
                minIndex[0] = -1;
                maxIndex[0] = -1;
            }
            if (nums[right] == minK) minIndex[0] = right;
            if (nums[right] == maxK) maxIndex[0] = right;

            if (minIndex[0] != -1 && maxIndex[0] != -1) {
                result[0] += Math.max(0, Math.min(minIndex[0], maxIndex[0]) - left[0] + 1);
            }
        });

        return result[0];
    }
}