Leetcode 346. Moving Average from Data Stream

Question

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

Explanation:

非常简单的题目，可以用queue或者arraylist或者array保存next的值。用一个sum存着总和，每次都计算一下平均值。

Code:

public class MovingAverage {

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

    }

    public double next(int val) {
        if (count < size) {
            count ++;
            q.offer(val);
            total += val;
            return total*1.0 / count;
        } else {
            int remove = q.poll();
            q.offer(val);
            total -= remove;
            total += val;
            return total*1.0/ size;
        }


    }
}