3.7.11 编程求1!+2!+3!+...20!的值
public class P3711 {
public static void main(String[] args) {
long sum=0,n=1;
for (int i=1;i<=20;i++) {
n=1;
for (int j=1;j<=i;j++) {
n*=j;
}
sum+=n;
System.out.print("i="+i+" sum= "+sum+"/n");
}
}
}
后来在社区论坛问了问,根据高手的思路,改进了一下:)
public class P3711 {
public static void main(String[] args) {
long sum=0,n=1;
for (int i=1;i <=20;i++) {
n*=i;
sum+=n;
System.out.print("i="+i+" sum= "+sum+"/n");
}
}
}