队列练习

数据流中的移动平均值

https://leetcode-cn.com/problems/moving-average-from-data-stream/

class MovingAverage {
    double sum;
    double[] l;
    int start;
    int n;
    public MovingAverage(int size) {
        l = new double[size];
        sum = n = start = 0;
    }
    public double next(int val) {
        n++;
        sum += val;
        if(n >= l.length){
            int de = (n - 1) % l.length;
            sum -= l[de];
            l[de] = val;
            return sum / l.length;
        }
        else{
            l[n - 1] = val;
            return sum / n;
        }
    }
}