Order book

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.

Restrictions:30s256Mb 1 Score Packages

Feel free to create an issue if you need an extra library from the standard Ubuntu repository.

Name	Version	Description
libc6-dev	2.39-0ubuntu8.7	GNU C Library: Development Libraries and Header Files Contains the symlinks, headers, and object files needed to compile and link programs which use the standard C library.
libclang-common-14-dev	1:14.0.6-19build4	Clang library - Common development package Clang project is a C, C++, Objective C and Objective C++ front-end based on the LLVM compiler. Its goal is to offer a replacement to the GNU Compiler Collection (GCC). . Clang implements all of the ISO C++ 1998, 11, 14 and 17 standards and also provides most of the support of C++20. . This package contains the Clang generic headers.
libclang-common-15-dev	1:15.0.7-14build3	Clang library - Common development package Clang project is a C, C++, Objective C and Objective C++ front-end based on the LLVM compiler. Its goal is to offer a replacement to the GNU Compiler Collection (GCC). . Clang implements all of the ISO C++ 1998, 11, 14 and 17 standards and also provides most of the support of C++20. . This package contains the Clang generic headers.
libclang-common-16-dev	1:16.0.6-23ubuntu4	Clang library - Common development package Clang project is a C, C++, Objective C and Objective C++ front-end based on the LLVM compiler. Its goal is to offer a replacement to the GNU Compiler Collection (GCC). . Clang implements all of the ISO C++ 1998, 11, 14 and 17 standards and also provides most of the support of C++20. . This package contains the Clang generic headers.
libclang-common-17-dev	1:17.0.6-9ubuntu1	Clang library - Common development package Clang project is a C, C++, Objective C and Objective C++ front-end based on the LLVM compiler. Its goal is to offer a replacement to the GNU Compiler Collection (GCC). . Clang implements all of the ISO C++ 1998, 11, 14 and 17 standards and also provides most of the support of C++20. . This package contains the Clang generic headers.
libclang-common-18-dev	1:18.1.3-1ubuntu1	Clang library - Common development package Clang project is a C, C++, Objective C and Objective C++ front-end based on the LLVM compiler. Its goal is to offer a replacement to the GNU Compiler Collection (GCC). . Clang implements all of the ISO C++ 1998, 11, 14 and 17 standards and also provides most of the support of C++20. . This package contains the Clang generic headers.
libclang-common-19-dev	1:19.1.1-1ubuntu1~24.04.2	Clang library - Common development package Clang project is a C, C++, Objective C and Objective C++ front-end based on the LLVM compiler. Its goal is to offer a replacement to the GNU Compiler Collection (GCC). . Clang implements all of the ISO C++ 1998, 11, 14 and 17 standards and also provides most of the support of C++20. . This package contains the Clang generic headers.
libclang-common-20-dev	1:20.1.2-0ubuntu1~24.04.3	Clang library - Common development package Clang project is a C, C++, Objective C and Objective C++ front-end based on the LLVM compiler. Its goal is to offer a replacement to the GNU Compiler Collection (GCC). . Clang implements all of the ISO C++ 1998, 11, 14 and 17 standards and also provides most of the support of C++20. . This package contains the Clang generic headers.
libcrypt-dev	1:4.4.36-4build1	libcrypt development files This package contains the files needed for developing applications that use libcrypt.
libgcc-10-dev	10.5.0-4ubuntu2.1	GCC support library (development files) This package contains the headers and static library files necessary for building C programs which use libgcc, libgomp, libquadmath, libssp or libitm.
libgcc-11-dev	11.5.0-1ubuntu1~24.04.1	GCC support library (development files) This package contains the headers and static library files necessary for building C programs which use libgcc, libgomp, libquadmath, libssp or libitm.
libgcc-12-dev	12.4.0-2ubuntu1~24.04.1	GCC support library (development files) This package contains the headers and static library files necessary for building C programs which use libgcc, libgomp, libquadmath, libssp or libitm.
libgcc-13-dev	13.3.0-6ubuntu2~24.04.1	GCC support library (development files) This package contains the headers and static library files necessary for building C programs which use libgcc, libgomp, libquadmath, libssp or libitm.
libgcc-14-dev	14.2.0-4ubuntu2~24.04.1	GCC support library (development files) This package contains the headers and static library files necessary for building C programs which use libgcc, libgomp, libquadmath, libssp or libitm.
libobjc-13-dev	13.3.0-6ubuntu2~24.04.1	Runtime library for GNU Objective-C applications (development files) This package contains the headers and static library files needed to build GNU ObjC applications.
libssl-dev	3.0.13-0ubuntu3.11	Secure Sockets Layer toolkit - development files This package is part of the OpenSSL project's implementation of the SSL and TLS cryptographic protocols for secure communication over the Internet. . It contains development libraries, header files, and manpages for libssl and libcrypto.
libstdc++-10-dev	10.5.0-4ubuntu2.1	GNU Standard C++ Library v3 (development files) This package contains the headers and static library files necessary for building C++ programs which use libstdc++. . libstdc++-v3 is a complete rewrite from the previous libstdc++-v2, which was included up to g++-2.95. The first version of libstdc++-v3 appeared in g++-3.0.
libstdc++-11-dev	11.5.0-1ubuntu1~24.04.1	GNU Standard C++ Library v3 (development files) This package contains the headers and static library files necessary for building C++ programs which use libstdc++. . libstdc++-v3 is a complete rewrite from the previous libstdc++-v2, which was included up to g++-2.95. The first version of libstdc++-v3 appeared in g++-3.0.
libstdc++-12-dev	12.4.0-2ubuntu1~24.04.1	GNU Standard C++ Library v3 (development files) This package contains the headers and static library files necessary for building C++ programs which use libstdc++. . libstdc++-v3 is a complete rewrite from the previous libstdc++-v2, which was included up to g++-2.95. The first version of libstdc++-v3 appeared in g++-3.0.
libstdc++-13-dev	13.3.0-6ubuntu2~24.04.1	GNU Standard C++ Library v3 (development files) This package contains the headers and static library files necessary for building C++ programs which use libstdc++. . libstdc++-v3 is a complete rewrite from the previous libstdc++-v2, which was included up to g++-2.95. The first version of libstdc++-v3 appeared in g++-3.0.
libstdc++-14-dev	14.2.0-4ubuntu2~24.04.1	GNU Standard C++ Library v3 (development files) This package contains the headers and static library files necessary for building C++ programs which use libstdc++. . libstdc++-v3 is a complete rewrite from the previous libstdc++-v2, which was included up to g++-2.95. The first version of libstdc++-v3 appeared in g++-3.0.
libtbb-dev	2021.11.0-2ubuntu2	parallelism library for C++ - development files TBB is a library that helps you leverage multi-core processor performance without having to be a threading expert. It represents a higher-level, task-based parallelism that abstracts platform details and threading mechanism for performance and scalability. . (Note: if you are a user of the i386 architecture, i.e., 32-bit Intel or compatible hardware, this package only supports Pentium4-compatible and higher processors.) . This package includes the TBB development files.

Back to listApr 10, 2026 17:46

Tim Zhamoidin

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Challenge History

Date	Challenger	Cost	Type	Status
Oct 5, 2026 19:00	Andrew Epstein	10.00	Custom	Solution Broken

Run Statistics

#	Date	Score	Wall Time	CPU User	CPU System	Memory	Error
1	Oct 5, 2026 19:07	0	12,150,155	1,866,000	0	20,480	No answer to stdout. Died or killed?
2	Apr 10, 2026 17:41	74,607	73,166,764	41,260,000	2,012,000	2,502,656
3	Apr 10, 2026 17:41	74,679	68,202,297	42,307,000	1,007,000	2,490,368
4	Apr 10, 2026 17:41	74,879	62,755,891	42,420,000	1,010,000	2,285,568
5	Apr 10, 2026 17:41	74,903	65,954,642	42,434,000	1,010,000	2,502,656
6	Apr 10, 2026 17:46	75,009	63,882,295	42,494,000	1,011,000	2,506,752
7	Apr 10, 2026 17:46	75,028	69,957,103	42,504,000	1,012,000	2,285,568
8	Apr 11, 2026 16:38	75,084	68,586,824	42,537,000	1,012,000	2,293,760
9	Apr 11, 2026 16:37	75,114	68,013,863	42,553,000	1,013,000	2,506,752
10	Apr 10, 2026 17:41	75,176	64,082,767	42,588,000	1,014,000	2,494,464
11	Apr 11, 2026 16:37	75,183	69,604,404	42,592,000	1,014,000	2,281,472
12	Apr 11, 2026 16:38	75,228	72,081,740	42,618,000	1,014,000	2,506,752
13	Apr 11, 2026 16:37	75,262	71,329,125	42,637,000	1,015,000	2,498,560
14	Apr 10, 2026 17:46	75,328	69,828,069	42,674,000	1,016,000	2,281,472
15	Apr 11, 2026 16:38	75,448	70,215,584	42,743,000	1,017,000	2,281,472
16	Apr 10, 2026 17:46	75,462	68,159,216	43,768,000	0	2,502,656
17	Apr 10, 2026 17:41	75,631	70,294,860	42,870,000	996,000	2,355,200
18	Apr 10, 2026 17:46	75,636	76,202,497	41,875,000	1,994,000	2,285,568
19	Apr 10, 2026 17:41	75,669	70,997,256	41,894,000	1,994,000	2,498,560
20	Apr 10, 2026 17:46	75,698	78,524,537	41,910,000	1,995,000	2,285,568
21	Apr 10, 2026 17:46	75,800	69,121,555	41,966,000	1,998,000	2,519,040
22	Apr 10, 2026 17:46	75,831	71,843,780	41,983,000	1,999,000	2,281,472
23	Apr 10, 2026 17:41	75,872	67,925,666	43,006,000	1,000,000	2,285,568
24	Apr 10, 2026 17:46	75,879	70,231,470	42,010,000	2,000,000	2,281,472
25	Apr 10, 2026 17:41	76,014	66,221,004	43,086,000	1,002,000	2,510,848

Model	Intel(R) Xeon(R) CPU E3-1271 v3 @ 3.60GHz
Cores	1