Moving Average from Data Stream(Easy)

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

Java 实现

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

public double next(int val) {
    q.offer(val);
    sum += val;

    if(q.size() > size) {
        sum -= q.peek();
        q.poll();
    }
    return 1.0 * sum / q.size();
}