Find Median from Data Stream problem solved

Author: hasibulislam999

Data Stream/295_find-median-from-data-stream.js

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+/**
+ * Title: Find Median from Data Stream
+ * Description: The median is the middle value in an ordered integer list. If the size of the list is even, there is no middle value, and the median is the mean of the two middle values.
+ * Author: Hasibul Islam
+ * Date: 28/04/2023
+ */
+
+class MedianFinder {
+  //Initilize max and min heap
+  constructor() {
+    this.minHeap = new MinPriorityQueue(); //supported by leetcode
+    this.maxHeap = new MaxPriorityQueue();
+  }
+
+  addNum(num) {
+    //add to min and pop the top for max to keep them in the order that we want
+    this.minHeap.enqueue(num);
+    this.maxHeap.enqueue(this.minHeap.dequeue().element);
+    //balance them
+    if (this.minHeap.size() < this.maxHeap.size()) {
+      this.minHeap.enqueue(this.maxHeap.dequeue().element);
+    }
+    //console.log(this.minHeap.toArray(), this.maxHeap.toArray()) //run this to understand better
+  }
+
+  findMedian() {
+    if (this.minHeap.size() > this.maxHeap.size())
+      // if one is bigger 21 and 345 example just pop from 345(min heap)
+      return this.minHeap.front().element;
+    else
+      return (this.minHeap.front().element + this.maxHeap.front().element) / 2; // 21 and 34 example, pop 1 and 3 and find average
+  }
+}
+
+/**
+ * Your MedianFinder object will be instantiated and called as such:
+ * var obj = new MedianFinder()
+ * obj.addNum(num)
+ * var param_2 = obj.findMedian()
+ */