K Top Selling Books

Design a data structure that tracks cumulative book sales and returns the top sellers after each update. Tracking Top Selling Books We need to build a system that keeps track of total book sales. It should also give us a list of the top-selling books every time we update the sales data. Class Requirements You need to implement the BestSellerTracker class with the following methods: BestSellerTracker(): Sets up the tracker with no sales data initially. List<String> bestSellers(Map<String, Integer> sales, Integer k): Adds new sales numbers to the existing totals for each book. After updating the totals, it returns the top k book titles. Ranking Rules Sort the books using this order: Sales Count: Books with higher total sales come first. Alphabetical Order: If two books have the exact same sales total, pick the title that is "larger" alphabetically (for example, "beta" comes before "alpha"). Note: If the requested k is bigger than the total number of books tracked, simply return all the books in the correct order. Sample Cases Case 1: Input: ["BestSellerTracker","bestSellers","bestSellers"] [[],[{"a":5,"b":10,"c":15},2],[{"a":20,"b":20,"c":5},2]] Output: [null,["c","b"],["b","a"]] Breakdown: First Update: We add sales {a:5, b:10, c:15}. The totals are now {a:5, b:10, c:15}. The top 2 books are "c" (15) and "b" (10). Second Update: We add more sales {a:20, b:20, c:5} to the old totals. Book "a": 5 + 20 = 25 Book "b": 10 + 20 = 30 Book "c": 15 + 5 = 20 New totals are {a:25, b:30, c:20}. The top 2 are now "b" (30) and "a" (25). Case 2: Input: ["BestSellerTracker","bestSellers"] [[],[{"alpha":4,"beta":4,"gamma":1},5]] Output: [null,["beta","alpha","gamma"]] Breakdown: "alpha" and "beta" are tied with 4 sales each. Since "beta" is alphabetically larger than "alpha", "beta" is placed first. Technical Limits 0 <= sales.size() <= 10^4 0 <= sales[title] <= 10^6 1 <= title.length <= 100 1 <= k <= 10^4 The bestSellers method will be called at most 10^4 times.