题目(LeetCode #346)
Given a stream of integers and a window size, calculate the moving average of all integers in the sliding window.
Example:
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| 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
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题解
可使用固定大小的队列实现滑动窗口
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| import java.util.Queue;
import java.util.ArrayDeque;
class MovingAverage {
private int maxSize;
private double previousSum;
private Queue<Integer> data;
public MovingAverage(int maxSize) {
this.maxSize = maxSize;
data = new ArrayDeque<>();
}
public double next(int val) {
if (data.size() == maxSize)
previousSum -= data.poll();
data.add(val);
previousSum += val;
return previousSum / data.size();
}
}
class Solution {
public static void main(String[] args) {
MovingAverage m = new MovingAverage(3);
System.out.println(m.next(1));
System.out.println(m.next(10));
System.out.println(m.next(3));
System.out.println(m.next(5));
}
}
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