Given a stream of integers and a window size, calculate the moving average of all integers in the sliding window.

For example, MovingAverage m = new MovingAverage(3); m.next(1) = 1 m.next(10) = (1 + 10) / 2 m.next(3) = (1 + 10 + 3) / 3 m.next(5) = (10 + 3 + 5) / 3

Solution

public class MovingAverage {

    Queue<Integer> queue;
    int cap;
    int sum;
    /** Initialize your data structure here. */
    public MovingAverage(int size) {
        queue = new LinkedList<Integer>();
        cap = size;
        sum = 0;
    }

    public double next(int val) {
        sum += val;
        queue.offer(val);
        if(queue.size() > cap) sum -= queue.poll();
        return (double)sum / queue.size();
    }
}

/**
 * Your MovingAverage object will be instantiated and called as such:
 * MovingAverage obj = new MovingAverage(size);
 * double param_1 = obj.next(val);
 */