java基础练习 19

 

public class Ninetheen {
/*求1+2!+3!+...+20!的和*/
public static void main(String[] args){
int i,j;
long sum=0,jiecheng=1;
for(i=1;i<=20;i++){
jiecheng=1;
for(j=1;j<=i;j++)
jiecheng=jiecheng*j;
sum=sum+jiecheng;
}
System.out.println("1+2!+3!+...+20!的和是:"+sum);

}

}