# Moving Average from Data Stream

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

Implement the `MovingAverage` class:

• `MovingAverage(int size)` Initializes the object with the size of the window `size`.
• `double next(int val)` Returns the moving average of the last `size` values of the stream.

Example 1:

Input

```["MovingAverage", "next", "next", "next", "next"]
[[3], [1], [10], [3], [5]]
```

Output

```[null, 1.0, 5.5, 4.66667, 6.0]

```

Explanation

```MovingAverage movingAverage = new MovingAverage(3);
movingAverage.next(1); // return 1.0 = 1 / 1
movingAverage.next(10); // return 5.5 = (1 + 10) / 2
movingAverage.next(3); // return 4.66667 = (1 + 10 + 3) / 3
movingAverage.next(5); // return 6.0 = (10 + 3 + 5) / 3
```

Constraints:

• `1 <= size <= 1000`
• `-10`5` <= val <= 10`5
• At most `10`4 calls will be made to `next`.

## Solution

```/**
* @param {number} size
*/
var MovingAverage = function(size) {
this.n = size;
this.queue = [];
this.average = 0.0;
};

/**
* @param {number} val
* @return {number}
*/
MovingAverage.prototype.next = function(val) {
var removedVal;
if(this.queue.length >= this.n) {
removedVal = this.queue.shift();
this.average = this.average - removedVal;
}

this.queue.push(val);

this.average += val;
console.log(this.average / this.queue.length);
return this.average / this.queue.length;
};

var movingAverage = new MovingAverage(3);
movingAverage.next(1); // return 1.0 = 1 / 1
movingAverage.next(10); // return 5.5 = (1 + 10) / 2
movingAverage.next(3); // return 4.66667 = (1 + 10 + 3) / 3
movingAverage.next(5); // return 6.0 = (10 + 3 + 5) / 3```