feat: add solution for find median from data stream in python

Author: bujosa

alternative/hard/find_median_from_data_stream.py

@@ -0,0 +1,35 @@
+import heapq
+
+class MedianFinder:
+
+    def __init__(self):
+        """
+        initialize your data structure here.
+        """
+        self.minHeap = []
+        self.maxHeap = []
+        
+
+    def addNum(self, num: int) -> None:
+        heapq.heappush(self.maxHeap, -num)
+        heapq.heappush(self.minHeap, -heapq.heappop(self.maxHeap))
+        if len(self.maxHeap) < len(self.minHeap):
+            heapq.heappush(self.maxHeap, -heapq.heappop(self.minHeap))
+        
+
+    def findMedian(self) -> float:
+        if len(self.maxHeap) > len(self.minHeap):
+            return -self.maxHeap[0]
+        else:
+            return (-self.maxHeap[0] + self.minHeap[0]) / 2
+        
+
+medianFinder = MedianFinder()
+assert medianFinder.addNum(1) == None
+assert medianFinder.addNum(2) == None
+assert medianFinder.findMedian() == 1.5
+
+# Your MedianFinder object will be instantiated and called as such:
+# obj = MedianFinder()
+# obj.addNum(num)
+# param_2 = obj.findMedian()

src/readme.md

@@ -103,3 +103,4 @@
   - [x] [84. Largest rectangle in histogram](../src/hard/largest_rectangle_in_histogram.rs) -> [Problem Description](../src/hard/readme.md#84-largest-rectangle-in-histogram)
   - [x] [212. Word search II](../src/hard/word_search_ii.rs) -> [Problem Description](../src/hard/readme.md#212-word-search-ii)
   - [x] [239. Sliding window maximum](../src/hard/sliding_window_maximum.rs) -> [Problem Description](../src/hard/readme.md#239-sliding-window-maximum)
+  - [ ] [295. Find median from data stream](../src/hard/find_median_from_data_stream.rs) -> [Problem Description](../src/hard/readme.md#295-find-median-from-data-stream)