Description

给定序列和window，输出moving average
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

class MovingAverage(object):

    def __init__(self, size):
        """
        Initialize your data structure here.
        :type size: int
        """
        self.size = size
        self.list = []
        self.cnt = 0
        self.sum = 0
    def next(self, val):
        """
        :type val: int
        :rtype: float
        """
        if self.cnt < self.size:
            self.list.append(val)
            self.sum += val
        else:
            head = self.list.pop(0)
            self.sum -= head
            self.list.append(val)
            self.sum += val
            self.cnt -=1
        
        self.cnt+=1
        return  1.0*self.sum / self.cnt
    
# Your MovingAverage object will be instantiated and called as such:
# obj = MovingAverage(size)
# param_1 = obj.next(val)