编辑代码

import java.util.Scanner;
// 1:无需package
// 2: 类名必须Main, 不可修改

public class Main {
  static int ans = 0;
    public static void main(String[] args) {
        Scanner scan = new Scanner(System.in);
        //在此输入您的代码...
        int[] res = new int[]{0,1,2,3,4,5,6,7,8,9};
        f(0,res);
        System.out.println(ans);

        scan.close();
    }
    public static void f(int k,int[] res)
    {
      if(k>10)
      {
        return;
      }
      if(k==10)
      {
        if(check(res))
        {
            ans++;
            return;
        } 
      }
      for(int i = k;i<res.length;i++)
      {
          int temp = res[i];
          res[i] = res[k];
          res[k] = temp;
          f(k+1,res);
          temp = res[k];
          res[k] = res[i];
          res[i] = temp;
      }
    }
    public static boolean check(int[] res)
    {
        boolean match = false;
        if(res[0]<res[1]&&res[0]<res[2]&&res[1]<res[3]&&res[1]<res[4]&&res[2]<res[4]&&res[2]<res[5]&&res[3]<res[6]&&res[3]<res[7]&&res[4]<res[7]&&res[4]<res[8]&&res[5]<res[8]&&res[5]<res[9])
        {
            match = true;
        }
        return match;
    }
}