得到山形数组的最少删除次数

/*
 * Solution in Java using Java Stream
 * The approach remains the same: find LIS and LDS for each index.
 * Java Stream is used to manage collections and operations more succinctly.
 */
import java.util.*;
import java.util.stream.IntStream;

public class StreamSolution {
    public int minimumMountainRemovals(int[] nums) {
        int n = nums.length;
        int[] lis = new int[n];
        int[] lds = new int[n];
        Arrays.fill(lis, 1);
        Arrays.fill(lds, 1);

        // Calculate LIS using streams
        IntStream.range(1, n).forEach(i -> {
            IntStream.range(0, i).forEach(j -> {
                if (nums[i] > nums[j]) {
                    lis[i] = Math.max(lis[i], lis[j] + 1);
                }
            });
        });

        // Calculate LDS using streams
        IntStream.range(0, n - 1).map(i -> n - 2 - i).forEach(i -> {
            IntStream.range(i + 1, n).forEach(j -> {
                if (nums[i] > nums[j]) {
                    lds[i] = Math.max(lds[i], lds[j] + 1);
                }
            });
        });

        int maxMountainLength = IntStream.range(1, n - 1).filter(i -> lis[i] > 1 && lds[i] > 1)
                .map(i -> lis[i] + lds[i] - 1).max().orElse(0);

        return n - maxMountainLength;
    }
}