java每日一练

题目：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。

public class FenShuQiuHe {

    public static void main(String[] args) {
        print();
    }
    public static void print(){
        double num = 0.0,sum = 0.0;
        double i = 2.0,j = 1.0,temp = 0;
        int count = 20;
        System.out.println("前"+count+"项之和为：");
        while(count>0){
            count--;
            num = i/j;
            sum += num; 
            temp = j;
            j = i;
            i = i+temp;
        }
        System.out.println(sum);
    }
}