编写一个Java程序？
package Javaapp;
public class Main {
public static void main(String[] args) {
double sum;
sum=0.0;
for(int i=1;i<=100;i++){
if(i%2!=0)
{
sum+= 1.0/i;
}else{
sum-=1.0/i;
}
System.out.println("1-1/2+1/3-1/4 + ……+1/99-1/ 100 ="+sum);
