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:
Design a data structure that tracks cumulative book sales and returns the top sellers after each update.
Implement the BestSellerTracker class:
BestSellerTracker() Initializes the tracker with empty sales state.List<String> bestSellers(Map<String, Integer> sales, Integer k) Adds each incoming sale count to the current total for that title, then returns the top k titles.Rank titles by:
If k is larger than the number of tracked titles, return all titles in ranked order.
After first update: totals are {a:5, b:10, c:15}.
After second update: totals become {a:25, b:30, c:20}. Top 2 titles are ["b","a"].
alpha and beta are tied on total sales, so lexicographically larger beta comes first.
0 <= sales.size() <= 10^40 <= sales[title] <= 10^61 <= title.length <= 1001 <= k <= 10^410^4 calls will be made to bestSellers.