java中有一分数序列：2/1，3/2，5/3，8/5，13/8，21/13，…求出这个数列的前20项之和

Question

    double total=0;
        int numerator=1,donominator=2,i=0,change ;
        while (i<=20) {
            total+=numerator/donominator;
            i++;
            change=donominator;
            donominator=numerator+donominator;
            numerator=change;


        }
        System.out.println(total);

最后的输出结果始终为0.0
求解

Answer 1

total+=numerator/donominator;
这是整除
应该写
total+=(double)numerator/(double)donominator;