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 listDec 28, 2025 19:18yenw0dyenw0dError
Source Code

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Challenge History
DateChallengerCostTypeStatus
Jul 5, 2026 20:22Victor Mercklé10.00CustomSolution Broken
Run Statistics
#DateScoreWall TimeCPU UserCPU SystemMemoryError
1Jul 5, 2026 20:22014,020,65004,456,00024,576No answer to stdout. Died or killed?
2Dec 28, 2025 19:1813,72925,244,4852,986,0004,977,0002,355,200
3Dec 28, 2025 15:5613,81427,920,0452,003,0006,009,0002,318,336
4Dec 28, 2025 15:5613,84030,505,4043,010,0005,017,0002,314,240
5Dec 28, 2025 15:5613,90731,343,0034,033,0004,033,0002,310,144
6Dec 28, 2025 19:1814,06622,870,6414,079,0004,079,0002,314,240
7Dec 28, 2025 19:1814,14827,858,1843,077,0005,129,0002,387,968
8Dec 28, 2025 15:5614,15925,382,5322,053,0006,159,0002,383,872
9Dec 28, 2025 15:5614,16925,606,5314,109,0004,109,0002,469,888
10Dec 28, 2025 15:5614,18423,738,4953,085,0005,142,0002,318,336
11Dec 28, 2025 19:1814,20025,334,2412,059,0006,177,0002,297,856
12Dec 28, 2025 15:5614,22124,191,6294,124,0004,124,0002,326,528
13Dec 28, 2025 19:1814,22927,858,3982,063,0006,190,0002,514,944
14Dec 28, 2025 15:5614,28424,567,9003,107,0005,178,0002,326,528
15Dec 28, 2025 15:5614,51430,361,4942,104,0006,314,0002,445,312
16Dec 28, 2025 19:1814,94531,745,9652,167,0006,501,0002,387,968