Sync LeetCode submission Runtime - 1 ms (87.96%), Memory - 20.9 MB (6.68%)

Author: jimit105

0346-moving-average-from-data-stream/README.md

@@ -0,0 +1,35 @@
+<p>Given a stream of integers and a window size, calculate the moving average of all integers in the sliding window.</p>
+
+<p>Implement the&nbsp;<code>MovingAverage</code> class:</p>
+
+<ul>
+	<li><code>MovingAverage(int size)</code> Initializes&nbsp;the object with the size of the window <code>size</code>.</li>
+	<li><code>double next(int val)</code> Returns the moving average of the last <code>size</code> values of the stream.</li>
+</ul>
+
+<p>&nbsp;</p>
+<p><strong class="example">Example 1:</strong></p>
+
+<pre>
+<strong>Input</strong>
+[&quot;MovingAverage&quot;, &quot;next&quot;, &quot;next&quot;, &quot;next&quot;, &quot;next&quot;]
+[[3], [1], [10], [3], [5]]
+<strong>Output</strong>
+[null, 1.0, 5.5, 4.66667, 6.0]
+
+<strong>Explanation</strong>
+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
+</pre>
+
+<p>&nbsp;</p>
+<p><strong>Constraints:</strong></p>
+
+<ul>
+	<li><code>1 &lt;= size &lt;= 1000</code></li>
+	<li><code>-10<sup>5</sup> &lt;= val &lt;= 10<sup>5</sup></code></li>
+	<li>At most <code>10<sup>4</sup></code> calls will be made to <code>next</code>.</li>
+</ul>

0346-moving-average-from-data-stream/solution.py

@@ -0,0 +1,27 @@
+# Approach 2: Double ended queue
+
+# Time: O(1)
+# Space: O(n), n = size of moving window
+
+from collections import deque
+
+class MovingAverage:
+
+    def __init__(self, size: int):
+        self.size = size
+        self.queue = deque()
+        self.window_sum = 0
+
+    def next(self, val: int) -> float:
+        self.queue.append(val)
+        count = len(self.queue)
+        tail = self.queue.popleft() if count > self.size else 0
+
+        self.window_sum = self.window_sum - tail + val
+
+        return self.window_sum / min(self.size, count)
+
+
+# Your MovingAverage object will be instantiated and called as such:
+# obj = MovingAverage(size)
+# param_1 = obj.next(val)