Maximum Profit from Unordered Stock Price Records

Problem: Compute Maximum Profit from Unordered Stock Price Records You are given n stock price records. Each record contains: date: a date in YYYY-MM-DD format stock: a stock symbol without spaces price: the price of that stock on that date, represented as a positive integer The records are not guaranteed to be sorted by date. You may complete at most one transaction: Buy one share of one stock on some day; Sell the same stock on a later day; You must buy before selling; Short selling is not allowed; If no positive profit can be made, the profit is 0. Compute the maximum profit obtainable over all stocks and dates using at most one transaction. Input Format n date_1 stock_1 price_1 date_2 stock_2 price_2 ... date_n stock_n price_n Output Format Output one integer: the maximum obtainable profit. Constraints 1 <= n <= 200000 date is in YYYY-MM-DD format stock has length from 1 to 20 1 <= price <= 10^9 The same stock may appear on multiple different dates Input records are not guaranteed to be sorted Example Input: 5 2024-01-03 AAPL 120 2024-01-01 AAPL 100 2024-01-02 AAPL 90 2024-01-04 AAPL 150 2024-01-01 MSFT 200 Output: 60 Explanation: Buy AAPL at 90 on 2024-01-02 and sell it at 150 on 2024-01-04, gaining profit 60. Example Input 5 2024-01-03 AAPL 120 2024-01-01 AAPL 100 2024-01-02 AAPL 90 2024-01-04 AAPL 150 2024-01-01 MSFT 200 Output 60