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 2, 2026 21:22JuneLJuneLError
Source Code

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Challenge History
DateChallengerCostTypeStatus
Oct 5, 2026 18:40Andrew Epstein10.00CustomSolution Broken
Run Statistics
#DateScoreWall TimeCPU UserCPU SystemMemoryError
1Oct 5, 2026 18:52017,637,49307,345,00024,576No answer to stdout. Died or killed?
2Mar 2, 2026 21:2367,16467,363,57834,960,0003,995,0002,375,680
3Mar 2, 2026 21:2268,66768,552,05033,853,0005,974,0002,318,336
4Mar 2, 2026 21:2268,75969,625,41834,895,0004,985,0002,269,184
5Mar 2, 2026 21:2269,18168,530,57235,110,0005,015,0002,326,528
6Mar 2, 2026 21:2371,42967,155,74836,377,0005,052,0002,498,560
7Mar 2, 2026 21:2372,20067,304,97737,888,0003,988,0002,473,984
8Mar 2, 2026 21:2373,94771,683,27037,902,0004,987,0002,310,144
9Mar 2, 2026 21:2274,35367,106,75838,111,0005,014,0002,478,080
10Mar 2, 2026 21:2374,82472,801,73637,343,0006,055,0002,449,408
11Mar 2, 2026 21:2276,43371,875,41037,279,0007,052,0002,465,792
12Mar 2, 2026 21:2377,36476,332,95540,883,0003,988,0002,510,848
13Mar 2, 2026 21:2277,37970,621,00839,894,0004,986,0002,318,336
14Mar 2, 2026 21:2279,75370,425,60941,229,0005,028,0002,510,848
15Mar 2, 2026 21:2379,86077,888,50340,278,0006,041,0002,420,736
16Mar 2, 2026 21:2380,15073,867,94340,424,0006,063,0002,306,048
17Mar 2, 2026 21:2380,27875,365,83440,488,0006,073,0002,457,600
18Mar 2, 2026 21:2281,00272,922,30140,984,0005,997,0002,363,392
19Mar 2, 2026 21:2281,02272,768,83940,994,0005,999,0002,514,944
20Mar 2, 2026 21:2282,06268,991,31742,533,0005,063,0002,506,752
21Mar 2, 2026 21:2283,31775,833,68542,284,0006,040,0002,478,080
22Mar 2, 2026 21:2287,82282,714,59944,945,0005,992,0002,441,216