package javafirst;
public class HomeWork {
public static void main(String[] args){
System.out.println("输出一个菱形!");
for(int i = 0; i < 5; i ++){
for(int j = 5; j > i + 1; j--){
System.out.print(" ");
}
for(int k = 0; k < 2*i + 1; k++){
System.out.print("*");
}
System.out.println();
}
for(int i = 4;i > 0; i--){
for(int k = 4; k >= i; k--){
System.out.print(" ");
}
for(int j = 0;j < 2*i - 1; j++){
System.out.print("*");
}
System.out.println();
}
System.out.println("\n\n输出阶乘倒数之和!");
double sum =0 ,sum2 = 1;
int i = 1;
while(i <= 20){
sum2 *= i++;
sum += 1 / sum2;
}
System.out.println(sum);
}
}