package BiShi.AQY; import java.io.File; import java.io.FileNotFoundException; import java.util.Scanner; public class AQY_3 { public static long permutation(int N,int[] nums){ long[] list=new long[1]; int[] arr=new int[N]; for(int i=1;i<=N;i++){ arr[i-1]=i; } helper(arr,0,list,nums); return list[0]; } public static boolean check(int[] arr,int[] nums){ for (int i = 0; i arr[i+1]){ return false; } } return true; } public static void helper(int[] arr,int start,long[] list,int[] nums) { if((start==arr.length-1)&&check(arr,nums)){ list[0]=list[0]+1; list[0]=list[0]%(1000000000+7); }else{ for(int i=start;i