Java利用while循环计算1+1/2!+1/3!……+1/20!

 1 public static void main(String[] args) {
 2         double n = 1, sum = 0;
 3         while (n <= 20) {
 4             sum += 1 / Factorial(n);
 5             n++;
 6         }
 7         System.out.println(sum);
 8
 9     }
10
11     static double Factorial(double m) {
12         if (m == 1 || m == 0) {
13             return 1;
14         } else {
15             return (m * Factorial(m - 1));
16         }
17     }

 1 public static void main(String[] args) {
 2
 3         double n = 1, j = 1, sum = 0;
 4         while(n <= 20){
 5             j = j*n;
 6             sum += 1/j;
 7             n++;
 8         }
 9         System.out.println(sum);
10     }