Package g2001_2100.s2034_stock_price_fluctuation

Class StockPrice

java.lang.Object
g2001_2100.s2034_stock_price_fluctuation.StockPrice
public class StockPrice extends java.lang.Object
2034 - Stock Price Fluctuation.

Medium

You are given a stream of records about a particular stock. Each record contains a timestamp and the corresponding price of the stock at that timestamp.

Unfortunately due to the volatile nature of the stock market, the records do not come in order. Even worse, some records may be incorrect. Another record with the same timestamp may appear later in the stream correcting the price of the previous wrong record.

Design an algorithm that:

  • Updates the price of the stock at a particular timestamp, correcting the price from any previous records at the timestamp.
  • Finds the latest price of the stock based on the current records. The latest price is the price at the latest timestamp recorded.
  • Finds the maximum price the stock has been based on the current records.
  • Finds the minimum price the stock has been based on the current records.

Implement the StockPrice class:

  • StockPrice() Initializes the object with no price records.
  • void update(int timestamp, int price) Updates the price of the stock at the given timestamp.
  • int current() Returns the latest price of the stock.
  • int maximum() Returns the maximum price of the stock.
  • int minimum() Returns the minimum price of the stock.

Example 1:

Input [“StockPrice”, “update”, “update”, “current”, “maximum”, “update”, “maximum”, “update”, “minimum”] [ [], [1, 10], [2, 5], [], [], [1, 3], [], [4, 2], []]

Output: [null, null, null, 5, 10, null, 5, null, 2]

Explanation:

StockPrice stockPrice = new StockPrice();

stockPrice.update(1, 10); // Timestamps are [1] with corresponding prices [10].

stockPrice.update(2, 5); // Timestamps are [1,2] with corresponding prices [10,5].

stockPrice.current(); // return 5, the latest timestamp is 2 with the price being 5.

stockPrice.maximum(); // return 10, the maximum price is 10 at timestamp 1.

stockPrice.update(1, 3); // The previous timestamp 1 had the wrong price, so it is updated to 3. // Timestamps are [1,2] with corresponding prices [3,5].

stockPrice.maximum(); // return 5, the maximum price is 5 after the correction.

stockPrice.update(4, 2); // Timestamps are [1,2,4] with corresponding prices [3,5,2].

stockPrice.minimum(); // return 2, the minimum price is 2 at timestamp 4.

Constraints:

  • 1 <= timestamp, price <= 109
  • At most 105 calls will be made in total to update, current, maximum, and minimum.
  • current, maximum, and minimum will be called only after update has been called at least once.

  • Constructor Summary

    Constructors
    Constructor
    Description
    StockPrice()
     

  • Method Summary

    Modifier and Type
    Method
    Description
    int
    current()
     
    int
    maximum()
     
    int
    minimum()
     
    void
    update(int timestamp, int price)
     

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

  • Constructor Details

    • StockPrice

      public StockPrice()

  • Method Details

    • update

      public void update(int timestamp, int price)

    • current

      public int current()

    • maximum

      public int maximum()

    • minimum

      public int minimum()