题解 | #小Q的排序#

import java.util.Scanner;

/**
 * QQ11 小Q的排序
 * @author d3y1
 */
public class Main {
    public static void main(String[] args){
        Scanner in = new Scanner(System.in);

        while(in.hasNext()){
            solution(in);
        }
    }

    /**
     * 模拟法: 穷举所有情形
     * @param in
     */
    private static void solution(Scanner in){
        int n = in.nextInt();
        int[] nums = new int[n];

        int min = Integer.MAX_VALUE;
        int max = Integer.MIN_VALUE;
        boolean isSorted = true;
        for(int i=0; i<n; i++){
            nums[i] = in.nextInt();
            if(min > nums[i]){
                min = nums[i];
            }
            if(max < nums[i]){
                max = nums[i];
            }

            if(i+1 < n){
                if(nums[i] > nums[i+1]){
                    isSorted = false;
                }
            }
        }
        
        int result;
        if(isSorted){
            result = 0;
        }else if(min==nums[0] || max==nums[n-1]){
            result = 1;
        }else if(min==nums[n-1] && max==nums[0]){
            result = 3;
        }else{
            result = 2;
        }

        System.out.println(result);
    }
}