赛码网----翻转数组

import java.util.Scanner;

public class Main {
    static int[] a = new int[100005];
    public static boolean solven(int n) {
        int flag = 0, left = 0, right = n-1;
        for(int i = 0; i < n - 1; ++i) {
            if(flag == 0 && a[i] > a[i+1]) {
                ++flag;
                left = i;
            }
            if(flag == 1 && a[i] < a[i+1]) {
                ++flag;
                right = i;
            }
            if(flag == 2 && a[i] > a[i+1]) return false;
        }
        if(left > 0 && a[right] < a[left-1]) return false;
        if(right < n-1 && a[left] > a[right+1]) return false;
        return true;
    }
    public static void main(String[] args) {
        Scanner cin = new Scanner(System.in);
        int n = cin.nextInt();
        for(int i = 0; i < n; ++i)
            a[i] = cin.nextInt();
        if(solven(n))
            System.out.println("yes");
        else
            System.out.println("no");
    }
}