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 23, 2026 22:47DmtryDmtryError
Source Code

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Challenge History
DateChallengerCostTypeStatus
Jul 5, 2026 16:13Victor Mercklé10.00CustomSolution Broken
Run Statistics
#DateScoreWall TimeCPU UserCPU SystemMemoryError
1Jul 5, 2026 16:13010,094,6281,766,00002,113,536expected "999999000 ", got "0 "
2Jul 5, 2026 16:1309,909,9251,749,00002,113,536expected "999999000 ", got "0 "
3Jul 5, 2026 16:1309,579,5531,744,00002,113,536expected "999999000 ", got "0 "
4Mar 23, 2026 22:474,21417,631,8072,444,00002,461,696
5Mar 24, 2026 13:414,25518,370,1432,468,00002,453,504
6Mar 23, 2026 22:474,36415,750,8752,531,00002,445,312
7Mar 23, 2026 22:474,41418,565,9632,560,00002,461,696
8Mar 24, 2026 13:414,49716,695,5311,304,0001,304,0002,486,272
9Mar 23, 2026 22:474,51421,435,3322,618,00002,535,424
10Mar 23, 2026 22:474,51723,158,9241,310,0001,310,0002,461,696
11Mar 23, 2026 22:474,53815,715,0142,632,00002,535,424
12Mar 24, 2026 13:414,55217,833,0761,320,0001,320,0002,465,792