Practice/Snapchat/Leetcode 2034. Stock Price Fluctuation

Leetcode 2034. Stock Price Fluctuation

CodingMust

Problem

You are building a real-time stock price tracking system that receives price updates throughout the trading day. The system must handle several challenges:

• Price updates can arrive out of chronological order (e.g., you might receive the price at timestamp 5 before receiving the price at timestamp 3)

• Price corrections can occur where a previously recorded price at a given timestamp needs to be updated with a new value

• The system must efficiently support queries for:

  • The current price (price at the most recent timestamp)
  • The maximum price across all recorded timestamps
  • The minimum price across all recorded timestamps

Design and implement a StockTracker class that supports these operations efficiently.

Requirements

1. Implement a constructor that initializes an empty price tracking system
2. Implement update(timestamp, price) which records or updates the stock price at the given timestamp
3. Implement current() which returns the price at the latest (highest) timestamp
4. Implement maximum() which returns the highest price across all timestamps
5. Implement minimum() which returns the lowest price across all timestamps
6. Handle price corrections properly (when update is called with an existing timestamp, replace the old price)
7. All query operations should be as efficient as possible

Constraints

• 1 ≤ timestamp ≤ 109
• 1 ≤ price ≤ 109
• At most 105 calls will be made to update, current, maximum, and minimum
• current, maximum, and minimum will only be called after at least one update
• All timestamps in update calls are unique at any given point (before corrections)

Examples

Example 1:

Operations: tracker = StockTracker() tracker.update(1, 100) // Record price 100 at timestamp 1 tracker.update(2, 150) // Record price 150 at timestamp 2 tracker.current() // Returns 150 (price at latest timestamp 2) tracker.maximum() // Returns 150 (highest price overall) tracker.minimum() // Returns 100 (lowest price overall)

Example 2:

Operations: tracker = StockTracker() tracker.update(5, 200) // Record price 200 at timestamp 5 tracker.update(1, 100) // Record price 100 at timestamp 1 (out of order) tracker.update(3, 150) // Record price 150 at timestamp 3 tracker.current() // Returns 200 (timestamp 5 is still latest) tracker.maximum() // Returns 200 tracker.minimum() // Returns 100

Example 3:

Operations: tracker = StockTracker() tracker.update(1, 100) // Record price 100 at timestamp 1 tracker.update(2, 200) // Record price 200 at timestamp 2 tracker.update(1, 120) // Correct timestamp 1 to price 120 tracker.current() // Returns 200 (latest timestamp 2) tracker.maximum() // Returns 200 tracker.minimum() // Returns 120 (old price 100 removed)