Java循环输出一个菱形与阶乘倒数

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("

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);

	}

}