add moving average from data stream

Author: fishercoder1534

README.md

@@ -34,6 +34,7 @@
 |370|[Range Addition](https://leetcode.com/problems/range-addition/)|[Solution](../../blob/master/MEDIUM/src/medium/RangeAddition.java)| O(n+k)|O(1) | Medium| 
 |350|[Intersection of Two Arrays II](https://leetcode.com/problems/intersection-of-two-arrays-ii/)|[Solution](../../blob/master/EASY/src/easy/IntersectionOfTwoArraysII.java)| O(m+n)|O((m+n)) could be optimized | Easy| HashMap, Binary Search
 |349|[Intersection of Two Arrays](https://leetcode.com/problems/intersection-of-two-arrays/)|[Solution](../../blob/master/EASY/src/easy/IntersectionOfTwoArrays.java)| O(m+n)|O(min(m,n)) | Easy| Two Pointers, Binary Search
+|346|[Moving Average from Data Stream](https://leetcode.com/problems/moving-average-from-data-stream/)|[Solution](../../blob/master/EASY/src/easy/MovingAveragefromDataStream.java)| O(1)|O(w)) | Easy| Queue
 |339|[Nested List Weight Sum](https://leetcode.com/problems/nested-list-weight-sum/)|[Solution](../../blob/master/EASY/src/easy/NestedListWeightSum.java)| O(n)|O(h)) | Easy| DFS
 |338|[Counting Bits](https://leetcode.com/problems/counting-bits/)|[Solution](../../blob/master/MEDIUM/src/medium/CountingBits.java)| O(n)|O(n) | Medium| 
 |325|[Maximum Size Subarray Sum Equals k](https://leetcode.com/problems/maximum-size-subarray-sum-equals-k/)|[Solution] | O(n)|O(n) | Medium| HashMap