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Implement a Simple Stock Exchange
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Implement a Simple Stock Exchange

HardPython

Problem

How would you implement a simple stock exchange matching engine?

Process orders in arrival order using price-time priority. Each order has a unique order_id, a side ("buy" or "sell"), an integer price, and an integer quantity.

Implement match_orders(orders). Return a dictionary containing trades, in execution order, and book, containing all remaining orders sorted by descending buy price and ascending sell price. A buy matches the lowest-priced sell when buy_price >= sell_price; a sell matches the highest-priced buy when sell_price <= buy_price. Execute each trade at the resting order's price.

Constraints

  • 1 <= len(orders) <= 5000
  • Each order contains a unique string order_id
  • side is either "buy" or "sell"
  • 1 <= price <= 10^9
  • 1 <= quantity <= 10^9
  • Orders are processed in the given arrival order
  • All quantities and prices are integers

Function Signature

def match_orders(orders):
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