题解 | #合唱队#

import java.util.*;
import java.util.concurrent.atomic.AtomicBoolean;

public class Main {
    static int x = 0;
    static int y = 0;

    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        // 注意 hasNext 和 hasNextLine 的区别
        int num = in.nextInt();
        int temp = num;
        int len = 0;
        int[] nums = new int[num];
        int[] left = new int[num];
        int[] right = new int[num];
        while (temp-- > 0) { // 注意 while 处理多个 case
           nums[len++] = in.nextInt();
        }
        left = lengthOfLIS(nums, num);
        int[] nums2 = new int[num];
        int j = 0;
        for (int i = num - 1; i >= 0; i--) {
            nums2[j++] = nums[i];
        }
        right = lengthOfLIS(nums2, num);
        int minnum = left[0] + right[len - 1];
        for (int k = 0; k < num ; k++) {
            minnum = Math.min(minnum, left[k] + right[num - 1 - k]);
        }
        System.out.println(minnum);
    }

    public static int[] lengthOfLIS(int[] nums, int len) {
        int [] dp = new int[len];
        dp[0] = 1;
        int [] res = new int[len];
        int maxnum = 1;
        for (int i = 0; i < len; i++) {
            dp[i] = 1;
            for (int j = 0; j < i; j++) {
                if (nums[i] > nums[j]) {
                    dp[i] = Math.max(dp[i], dp[j] + 1);
                }
            }
            maxnum = Math.max(maxnum, dp[i]);
            res[i] = i + 1 - maxnum;
        }
        return res;
    }
}