题解 | #合唱队#

import java.util.Scanner;

// 注意类名必须为 Main, 不要有任何 package xxx 信息
public class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        int n = in.nextInt();
        int[] arr = new int[n];
        for(int i = 0; i < n; i++){
            arr[i] = in.nextInt();
        }

        int[] left = new int[n];
        int[] right = new int[n];

        left[0] = 1;
        right[arr.length - 1] = 1;
        for(int i = 0; i < arr.length; i++){
            left[i] = 1;
            for(int j = 0; j < i; j++){
                if(arr[i] > arr[j]){
                    left[i] = Math.max(left[j] + 1, left[i]);
                }
            }
        }

        for(int i = arr.length - 1; i >= 0; i-- ){
            right[i] = 1;
            for(int j = arr.length -1; j >= i; j--){
                if(arr[i] > arr[j]){
                    right[i] = Math.max(right[i], right[j] + 1);
                }
            }
        }

        int max = left[0] + right[0] -1;
        for(int i = 0; i < arr.length; i++){
            max = Math.max(max, left[i] + right[i] -1);
        }

        System.out.println(arr.length - max);        
    }
}