Find Median from Data Stream

The median is the middle value in a sorted list of integers. Find Median from Data Stream The median is the middle value in a sorted list of integers. SWE heap data-structure streaming hard Frequency Single report Last asked 2026-01-04 Stage phone-screen · onsite-coding Find Median from Data Stream Problem Explanation The median is the number found in the exact middle of a sorted list. If the list has an odd number of items, the median is the middle number. If the list has an even number of items, there is no single middle value. In this case, the median is the average (mean) of the two numbers in the center. Simple Examples: For arr = [1, 2, 3], the middle is 2. The median is 2. For arr = [1, 2], the middle values are 1 and 2. The median is (1 + 2) / 2 = 1.5. Task Requirements You need to write a class called MedianFinder. It must support these actions: MedianFinder(): Sets up the class object. void addNum(int num): Adds the integer num into the data structure. double findMedian(): Calculates and returns the median of all the numbers added so far. Execution Walkthrough Example 1: Input Operations: ["MedianFinder", "addNum", "addNum", "findMedian", "addNum", "findMedian"] [[], [1], [2], [], [3], []] Output: [null, null, null, 1.5, null, 2.0] Step-by-Step Logic: // Initialize the object MedianFinder medianFinder = new MedianFinder(); // Add number 1. List is now [1] medianFinder.addNum(1); // Add number 2. List is now [1, 2] medianFinder.addNum(2); // Find median. The list is [1, 2]. // The average of 1 and 2 is 1.5. medianFinder.findMedian(); // return 1.5 // Add number 3. List is now [1, 2, 3] medianFinder.addNum(3); // Find median. The list is [1, 2, 3]. // The middle element is 2. medianFinder.findMedian(); // return 2.0 Operational Limits The value of num will be between -100,000 and 100,000. The function findMedian is only called when there is at least one number stored in the data structure.