Order book Yuriy Lyfenko

Simulate a sell-side order book and calculate the cost of a final purchase as fast as possible.

Input

1,000,000 order updates on STDIN, one per line:

  • + <price> <size> – add a new sell order
  • - <position> – delete the order at the given position
  • = <size> – buy <size> shares from the top of the order book

After all updates are processed, buy 1,000 shares from the top of the order book.

Output

Print the total cost of the final 1,000-share purchase to STDOUT.

Order Book Rules

Orders are sorted by price ascending (lower is better). Orders at the same price are sorted by arrival time (earlier first). Position 0 is the best (lowest-price) offer.

The = (buy) operation consumes shares starting from position 0. If an order is fully consumed, it is removed from the book.

Example

Input Order book state
+ 1137 100 (1137,100)
+ 1130 10 (1130,10), (1137,100)
+ 1130 50 (1130,10), (1130,50), (1137,100)
- 0 (1130,50), (1137,100)
+ 1150 200 (1130,50), (1137,100), (1150,200)
= 200 (1150,150)

Total cost of the last buy: 50 * 1130 + 100 * 1137 + 50 * 1150.

Back to listMay 6, 2026 16:06Dominique GarmierDominique GarmierError
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Run Statistics
#DateScoreWall TimeCPU UserCPU SystemMemoryError
1May 6, 2026 16:07018,777,2341,706,0001,706,000241,664Exit with code 1: HLBIN_BEGIN idx=0 chunk_bytes=7200 total_bytes=3972744 got=7200 f0VMRgIBAQAAAAAAAAAAAAMAPgABAAAA8FUBAAAAAABAAAAAAAAAAEiUPAAAAAAAAAAAAEAAOAAM AEAAKQAnAAYAAAAEAAAAQAAAAAAAAABAAAAAAAAAAEAAAAAAAAAAoAIAAAAAAACgAgAAAAAAAAgA AAAAAAAAAwAAAAQA...stderr