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 listOct 4, 2026 20:09Karthik ReddyKarthik ReddyError
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Run Statistics
#DateScoreWall TimeCPU UserCPU SystemMemoryError
1Oct 4, 2026 20:090278,864,850263,524,0004,160,0002,113,536expected "590000 ", got "seg 952 815 616 536 531 576 586 650 573 612 638 552 568 659 867 980 833 767 752 582 | dev 72.6 | book 219 lev 71 | ok:0000011111 "
2Oct 4, 2026 20:090279,545,124264,165,0004,201,0002,113,536expected "1101000 ", got "seg 1071 1371 1538 1531 1594 1620 1541 1293 1195 1202 1227 1302 1389 1281 1056 834 948 1047 1173 1043 | dev 116.6 | book 130 lev 75 | ok:0000011111 "
3Oct 4, 2026 20:090278,328,044263,317,0004,045,0002,113,536expected "1137000 ", got "seg 1011 920 868 857 673 560 622 832 895 722 651 599 558 616 585 619 642 842 852 979 | dev 82.5 | book 233 lev 126 | ok:0011111111 "