输入一个数，实现n!+(n-1)!+.....+2!+1!;

public static void main(String args[])
{
/*
* 输入一个数n。实现n!+(n-1)!+…..+2!+1!;
* */
int sum = 0;
int fac = 1;
System.out.println(“请输入一个整数:”);
Scanner scan = new Scanner(System.in);
int n = scan.nextInt();
for(int i = 1;i <= n;i++)
{
fac = fac * i;
sum += fac;
}
System.out.println(sum)；
}