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 listFeb 19, 2026 01:38Josu San MartinJosu San MartinError
Source Code

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Challenge History
DateChallengerCostTypeStatus
Jul 5, 2026 14:07Victor Mercklé10.00CustomSolution Broken
Run Statistics
#DateScoreWall TimeCPU UserCPU SystemMemoryError
1Jul 5, 2026 14:07010,424,0451,321,00002,117,632expected "999999000 ", got "4091005 "
2Jul 5, 2026 14:07010,400,5451,312,00002,117,632expected "999999000 ", got "4091005 "
3Jul 5, 2026 14:07010,538,3821,319,00002,117,632expected "999999000 ", got "4091005 "
4Feb 19, 2026 01:393,47217,404,45202,014,0002,306,048
5Feb 19, 2026 01:373,60921,349,80302,093,0002,318,336
6Feb 19, 2026 01:353,62918,040,37302,105,0002,400,256
7Feb 19, 2026 01:353,68417,619,92302,137,0002,514,944
8Feb 19, 2026 01:263,71422,883,53402,154,0002,478,080
9Feb 19, 2026 01:383,74820,404,8131,087,0001,087,0002,445,312
10Feb 19, 2026 01:373,74822,266,7731,087,0001,087,0002,297,856
11Feb 19, 2026 01:263,75219,227,1791,088,0001,088,0002,473,984
12Feb 19, 2026 01:393,77122,211,56002,187,0002,461,696
13Feb 19, 2026 01:383,77217,534,0401,094,0001,094,0002,502,656
14Feb 19, 2026 01:393,78622,727,5231,098,0001,098,0002,465,792
15Feb 19, 2026 01:373,81716,537,3101,107,0001,107,0002,285,568
16Feb 19, 2026 01:263,84720,469,27802,231,0002,437,120
17Feb 19, 2026 01:353,88321,609,8091,126,0001,126,0002,437,120
18Feb 19, 2026 01:384,02419,799,1541,167,0001,167,0002,355,200