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 30, 2026 03:26Dominique GarmierDominique GarmierScore: 7,332Success
Source Code

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Challenge History
DateChallengerCostTypeStatus
Apr 20, 2026 12:33Keefe10.00RecheckSolution Held
Run Statistics
#DateScoreWall TimeCPU UserCPU SystemMemoryError
1Mar 30, 2026 03:266,99318,545,0483,042,0001,014,0002,387,968
2Mar 30, 2026 03:267,01020,635,5403,050,0001,016,0002,392,064
3Mar 30, 2026 03:267,04323,941,9663,064,0001,021,0002,387,968
4Mar 30, 2026 03:267,08420,022,9483,082,0001,027,0002,392,064
5Mar 30, 2026 03:267,14118,476,3722,071,0002,071,0002,285,568
6Mar 30, 2026 03:267,21720,530,4902,093,0002,093,0002,424,832
7Mar 30, 2026 03:267,29022,304,4612,114,0002,114,0002,396,160
8Apr 20, 2026 12:347,32721,537,8642,125,0002,125,0002,363,392
9Apr 20, 2026 12:347,33221,022,5093,190,0001,063,0002,355,200
10Apr 20, 2026 12:347,37221,993,4972,138,0002,138,0002,359,296
11Mar 30, 2026 03:267,41420,525,6172,150,0002,150,0002,387,968
12Mar 30, 2026 03:267,47220,706,4142,167,0002,167,0002,424,832