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 listMar 5, 2026 23:08Sergey SerebryakovSergey SerebryakovError
Source Code

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Challenge History
DateChallengerCostTypeStatus
Jul 5, 2026 21:16Victor Mercklé28.03CustomSolution Broken
Run Statistics
#DateScoreWall TimeCPU UserCPU SystemMemoryError
1Jul 5, 2026 21:160177,683,487166,855,000016,384No answer to stdout. Died or killed?
2Mar 5, 2026 23:0834,52243,800,43919,022,0001,001,0002,498,560
3Mar 5, 2026 23:0834,78345,348,18518,157,0002,017,0002,297,856
4Mar 5, 2026 23:0835,17840,388,90820,403,00002,265,088
5Mar 5, 2026 23:0835,32943,308,73820,491,00002,514,944
6Mar 5, 2026 23:0835,67947,808,02319,660,0001,034,0002,514,944
7Mar 5, 2026 23:0836,03144,705,93319,903,000995,0002,510,848
8Mar 5, 2026 23:0836,03348,755,49619,904,000995,0002,498,560
9Mar 5, 2026 23:0836,04755,339,94719,912,000995,0002,277,376
10Mar 5, 2026 23:0836,15042,429,32919,969,000998,0002,514,944