K Top Selling Books
Examples
Example 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"]]
Explanation:
Example 2:
Input: ["BestSellerTracker","bestSellers"]
[[],[{"alpha":4,"beta":4,"gamma":1},5]]
Output: [null,["beta","alpha","gamma"]]
Explanation: