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 listSep 26, 2026 10:22Kevin HeaveyKevin HeaveyError
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Run Statistics
#DateScoreWall TimeCPU UserCPU SystemMemoryError
1Sep 26, 2026 10:22026,361,18717,082,000020,480Exit with code 5: size=9366245 lines=1000000 plus=728863 minus=260629 eq=10508 bad=0 pmin=518 pmax=2414 wpmin=737 wpmax=1972 smax=500 amax=834 qmax=56220 nl_end=1 dbg=1117stderr
2Sep 26, 2026 10:224,07711,355,1622,365,000020,480
3Sep 26, 2026 10:224,13211,423,5762,397,000020,480
4Sep 26, 2026 10:224,29311,563,1062,490,000020,480
5Sep 26, 2026 10:224,36010,958,8282,529,000020,480
6Sep 26, 2026 10:224,36710,993,4712,533,000020,480
7Sep 26, 2026 10:224,41510,994,0232,561,000020,480
8Sep 26, 2026 10:224,49311,736,2982,606,000020,480
9Sep 26, 2026 10:224,52011,716,7072,622,000020,480