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 25, 2026 21:40Kevin HeaveyKevin HeaveyError
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Run Statistics
#DateScoreWall TimeCPU UserCPU SystemMemoryError
1Sep 25, 2026 21:400109,809,84999,405,000020,480Exit with code 3: n=8964710 m=100600 f=8000 ops=1000000 +730734 -258750 =10516 p450..1726 s1..500 pos<=831 avg267 ge0 q1..56241 dep217 book1..850 avg522 fin181 front30580 ins<=836 ans=1175787 d6 tail=0 + 874 365|+ 1044 117|+ 1054 375|+ 1071 17|+ 1128 3...stderr