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 22, 2025 01:47Josu San MartinJosu San MartinError
Source Code

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Challenge History
DateChallengerCostTypeStatus
Sep 15, 2026 12:29Andrew Epstein10.00CustomSolution Broken
Run Statistics
#DateScoreWall TimeCPU UserCPU SystemMemoryError
1Sep 15, 2026 12:41010,612,969781,000020,480No answer to stdout. Died or killed?
2Dec 22, 2025 01:4735,41046,785,12320,538,00002,273,280
3Dec 22, 2025 01:4635,43142,588,82719,572,000978,0002,494,464
4Dec 22, 2025 01:4635,64043,732,10719,638,0001,033,0002,424,832
5Dec 22, 2025 01:4636,26043,475,17719,028,0002,003,0002,473,984
6Dec 22, 2025 01:4736,31249,320,58319,056,0002,005,0002,318,336
7Dec 22, 2025 01:4736,68152,289,58719,249,0002,026,0002,437,120
8Dec 22, 2025 01:4736,83844,904,96920,349,0001,017,0002,420,736
9Dec 22, 2025 01:4736,89748,053,58220,381,0001,019,0002,433,024
10Dec 22, 2025 01:4736,95548,415,37720,414,0001,020,0002,473,984
11Dec 22, 2025 01:4736,99748,661,78620,437,0001,021,0002,420,736
12Dec 22, 2025 01:4737,34349,994,39720,628,0001,031,0002,379,776
13Dec 22, 2025 01:4737,40547,499,40119,723,0001,972,0002,420,736