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 18, 2026 20:05Yuriy LyfenkoYuriy LyfenkoError
Source Code

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Challenge History
DateChallengerCostTypeStatus
Jul 5, 2026 16:11Victor Mercklé10.00CustomSolution Broken
Run Statistics
#DateScoreWall TimeCPU UserCPU SystemMemoryError
1Jul 5, 2026 16:11013,037,6435,172,00002,117,632expected "999999000 ", got "0 "
2Jul 5, 2026 16:11013,020,8605,273,00002,117,632expected "999999000 ", got "0 "
3Jul 5, 2026 16:11013,218,4985,285,00002,117,632expected "999999000 ", got "0 "
4Mar 18, 2026 20:133,66918,619,4041,064,0001,064,0002,396,160
5Mar 18, 2026 20:133,84814,895,9732,232,00002,379,776
6Mar 18, 2026 20:133,95317,400,0052,293,00002,351,104
7Mar 18, 2026 20:134,03114,872,6391,169,0001,169,0002,379,776
8Mar 18, 2026 20:064,04519,120,2332,346,00002,379,776
9Mar 18, 2026 20:064,04821,009,1532,348,00002,396,160
10Mar 18, 2026 20:134,05020,316,2432,349,00002,269,184
11Mar 18, 2026 20:134,05519,453,97002,352,0002,375,680
12Mar 18, 2026 20:134,08622,904,5741,185,0001,185,0002,342,912
13Mar 18, 2026 20:074,18419,908,6572,427,00002,387,968
14Mar 18, 2026 20:134,30319,024,7891,248,0001,248,0002,322,432
15Mar 18, 2026 20:064,35720,068,3012,527,00002,363,392
16Mar 18, 2026 20:064,36924,310,6182,534,00002,367,488
17Mar 18, 2026 20:134,38619,312,5032,544,00002,318,336
18Mar 18, 2026 20:064,40719,506,4592,556,00002,359,296
19Mar 18, 2026 20:074,45317,655,5142,583,00002,359,296
20Mar 18, 2026 20:064,53121,186,1031,314,0001,314,0002,383,872
21Mar 18, 2026 20:064,58422,054,1622,659,00002,322,432
22Mar 18, 2026 20:074,62120,860,0311,340,0001,340,0002,359,296
23Mar 18, 2026 20:064,65921,071,5702,702,00002,531,328
24Mar 18, 2026 20:064,89715,891,9232,840,00002,318,336
25Mar 18, 2026 20:056,11623,699,3503,547,00002,383,872
26Mar 18, 2026 20:056,15919,037,1973,572,00002,531,328
27Mar 18, 2026 20:056,49120,633,6942,510,0001,255,0002,367,488
28Mar 18, 2026 20:056,49719,509,9633,768,00002,367,488
29Mar 18, 2026 20:056,58618,676,8313,820,00002,342,912
30Mar 18, 2026 20:056,96919,976,6142,021,0002,021,0002,531,328
31Mar 18, 2026 20:057,03422,847,8113,060,0001,020,0002,523,136
32Mar 18, 2026 20:057,13320,639,6953,103,0001,034,0002,539,520
33Mar 18, 2026 20:057,15924,690,3012,076,0002,076,0002,318,336