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 listAug 31, 2026 13:35Tomislav TunkovicTomislav TunkovicError
Source Code

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Challenge History
DateChallengerCostTypeStatus
Sep 4, 2026 13:42Victor Mercklé29.20CustomSolution Broken
Run Statistics
#DateScoreWall TimeCPU UserCPU SystemMemoryError
1Sep 4, 2026 14:2509,385,4091,224,000024,576expected "1650500 ", got "1677674 "
2Sep 4, 2026 14:2509,307,0611,223,000024,576expected "1650500 ", got "1677674 "
3Sep 4, 2026 14:2509,306,1611,226,000024,576expected "1650500 ", got "1677674 "
4Aug 31, 2026 13:351,8939,184,0881,098,000024,576
5Aug 31, 2026 13:351,9329,134,1691,121,000024,576
6Aug 31, 2026 13:351,9639,127,2961,139,000024,576
7Aug 31, 2026 13:351,9709,154,7671,143,000024,576
8Aug 31, 2026 13:351,9849,155,7571,151,000024,576
9Aug 31, 2026 13:352,0179,224,6921,170,000024,576
10Aug 31, 2026 13:352,0179,359,3981,170,000024,576
11Aug 31, 2026 13:352,0539,212,4721,191,000024,576
12Aug 31, 2026 13:352,1659,305,6911,256,000024,576