package nothh; public class mmm { public static void main(String[] args) { // TODO Auto-generated method stub //相比起阶乘之和,阶乘的倒数和就需要用到float或者是double. float x = 0; float y = 0; int z = 20; while(z>0) { x = z; for(int j = z - 1; j > 0; j--) { x = j * x;
package four; public class fouronetwo { public static void main(String args[]){ double sum = 0,a = 1; int i = 1; while(i <= 20) { sum = sum+a; i = i+1; a = a*(1.0/i); } System.out.println(sum); } } 解释:当i=1, sum=1, i=2, a=1*(1/2); 当i=2, sum=1+1*1/2, i
1.if 是单分支语句,使用格式如下: if condition ; then statement ….. fi 2.if … else 是双分支语句,使用格式如下: if condition ; then statement …. else statement …. fi 3.if …elif…elif…else 是多分支语句,使用格式如下: if condition ; then statement …. elif condition ; then statement ….. elif co