题解 | #合唱队#

import java.util.*;
public class Main {
    public static void main(String[] args) {
        Scanner scan = new Scanner(System.in);
        while (scan.hasNext()) {
            int n = scan.nextInt();
            int[] arr = new int[n];
            int[] left = new int[n];
            int[] right = new int[n];
            for (int i = 0; i < n; i++) arr[i] = scan.nextInt();
            //fill left
            for (int i = 0; i < n; i++) {
                left[i] = 1;
                for (int j = 0; j < i; j++) {
                    if (arr[i] > arr[j]) {
                        left[i] = Math.max(left[i], left[j] + 1);
                    }
                }
            }
            // fill right
            for (int i = n - 1; i >= 0; i--) {
                right[i] = 1;
                for (int j = n - 1; j > i; j--) {
                    if (arr[j] < arr[i]) {
                        right[i] = Math.max(right[i], right[j] + 1);
                    }
                }
            }
            int max = 1;
            for (int i = 0; i < n; i++) {
                max = Math.max(max, left[i] + right[i] - 1);
            }
            System.out.println(n - max);
        }
    }
}