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 listJul 11, 2025 01:20Alexey IlyukhovAlexey IlyukhovError
Source Code

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Challenge History
DateChallengerCostTypeStatus
Oct 5, 2026 18:22Andrew Epstein10.00CustomSolution Broken
Run Statistics
#DateScoreWall TimeCPU UserCPU SystemMemoryError
1Oct 5, 2026 18:28030,002,536,30929,990,229,0001,003,00016,384Killed by timeout
2Jul 11, 2025 01:20141,228105,315,82178,916,0002,996,0002,412,544
3Jul 11, 2025 01:20141,867110,831,31678,270,0004,013,0002,310,144
4Jul 11, 2025 01:20143,795110,217,64180,387,0003,014,0002,510,848
5Jul 11, 2025 01:20144,719109,846,08481,939,0001,998,0002,420,736
6Jul 11, 2025 01:20148,712108,826,64183,245,0003,008,0002,523,136
7Jul 11, 2025 01:20152,322119,328,07787,344,0001,003,0002,486,272
8Jul 11, 2025 01:20153,545111,846,59585,054,0004,002,0002,301,952
9Jul 11, 2025 01:20158,371120,613,08786,863,0004,992,0002,486,272
10Jul 11, 2025 01:20161,712118,583,59790,800,0002,993,0002,387,968