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 listDec 28, 2025 18:04Josu San MartinJosu San MartinError
Source Code

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Challenge History
DateChallengerCostTypeStatus
Sep 11, 2026 13:11Andrew Epstein17.74CustomSolution Broken
Run Statistics
#DateScoreWall TimeCPU UserCPU SystemMemoryError
1Sep 11, 2026 13:11020,903,11110,810,000016,384No answer to stdout. Died or killed?
2Dec 28, 2025 18:0420,53438,770,47911,910,00002,383,872
3Dec 28, 2025 18:0420,84833,640,83610,077,0002,015,0002,510,848
4Dec 28, 2025 18:0420,92928,709,45211,128,0001,011,0002,400,256
5Dec 28, 2025 18:0420,99134,974,92510,146,0002,029,0002,387,968
6Dec 28, 2025 18:0421,16427,163,15712,275,00002,334,720
7Dec 28, 2025 18:0421,23330,214,49412,315,00002,412,544
8Dec 28, 2025 18:0421,46633,235,81712,450,00002,449,408
9Dec 28, 2025 18:0421,66029,084,96812,563,00002,482,176
10Dec 28, 2025 18:0421,74530,216,96111,561,0001,051,0002,461,696
11Dec 28, 2025 18:0421,77129,083,19211,575,0001,052,0002,379,776
12Dec 28, 2025 18:0421,77829,881,91011,579,0001,052,0002,392,064
13Dec 28, 2025 18:0421,82432,080,41411,604,0001,054,0002,355,200
14Dec 28, 2025 18:0421,85731,657,86511,621,0001,056,0002,498,560
15Dec 28, 2025 18:0421,92129,988,39012,714,00002,334,720
16Dec 28, 2025 18:0421,97646,449,87212,746,00002,441,216
17Dec 28, 2025 18:0422,02141,326,16412,772,00002,510,848
18Dec 28, 2025 18:0422,04033,621,26011,718,0001,065,0002,375,680
19Dec 28, 2025 18:0422,28132,716,92711,929,000994,0002,347,008