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 26, 2026 14:39Dominique GarmierDominique GarmierError
Source Code

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Challenge History
DateChallengerCostTypeStatus
Jul 5, 2026 18:36Victor Mercklé10.00CustomSolution Broken
Run Statistics
#DateScoreWall TimeCPU UserCPU SystemMemoryError
1Jul 5, 2026 18:36012,032,9292,003,000020,480No answer to stdout. Died or killed?
2Mar 26, 2026 14:397,43821,393,6104,314,00002,359,296
3Mar 26, 2026 14:487,55223,575,3622,190,0002,190,0002,359,296
4Mar 26, 2026 14:397,60326,370,2682,205,0002,205,0002,367,488
5Mar 26, 2026 14:487,61627,998,9213,313,0001,104,0002,371,584
6Mar 26, 2026 14:487,62823,400,0572,212,0002,212,0002,486,272
7Mar 26, 2026 14:397,63823,497,6054,430,00002,281,472
8Mar 26, 2026 14:487,65525,252,2153,330,0001,110,0002,281,472
9Mar 26, 2026 14:487,66923,296,5623,336,0001,112,0002,363,392
10Mar 26, 2026 14:487,67627,536,8443,339,0001,113,0002,375,680
11Mar 26, 2026 14:397,68623,117,9933,344,0001,114,0002,367,488
12Mar 26, 2026 14:487,68624,535,6463,344,0001,114,0002,285,568
13Mar 26, 2026 14:397,69018,119,3663,345,0001,115,0002,281,472
14Mar 26, 2026 14:487,70321,956,4183,351,0001,117,0002,371,584
15Mar 26, 2026 14:397,80226,744,1633,394,0001,131,0002,363,392
16Mar 26, 2026 14:397,80221,194,3473,394,0001,131,0002,371,584
17Mar 26, 2026 14:397,87122,374,1933,424,0001,141,0002,371,584
18Mar 26, 2026 14:397,88622,270,1713,431,0001,143,0002,371,584
19Mar 26, 2026 14:487,94125,690,1293,455,0001,151,0002,355,200