Large integer multiplication

Multiply two large unsigned integers as fast as possible.

Input

Exactly 500,000 bytes on STDIN: two unsigned integers encoded back-to-back, each 250,000 bytes, in little-endian byte order.

Output

Write exactly 500,000 bytes to STDOUT containing the product in little-endian byte order.

Restrictions:600s256Mb 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.

Date	Author	Language	Status	Score
Apr 21, 2026 10:42	Charles Cabergs	CPPg++13.3.0	Success	11,312
Apr 21, 2026 09:51	Dominique Garmier	CPPclang++20.1.2	Success	15,866
Apr 21, 2026 09:48	Dominique Garmier	CPPclang++20.1.2	Success	16,435
Apr 21, 2026 09:24	Dominique Garmier	CPPclang++20.1.2	Success	8,598
Apr 21, 2026 09:20	Dominique Garmier	CPPclang++20.1.2	Success	8,356
Apr 21, 2026 09:19	Dominique Garmier	CPPclang++20.1.2	Error
Apr 21, 2026 09:16	Dominique Garmier	CPPclang++20.1.2	Success	8,397
Apr 21, 2026 08:51	Charles Cabergs	CPPg++13.3.0	Success	11,205+83.00 RP
Apr 21, 2026 08:30	Dominique Garmier	CPPclang++20.1.2	Success	8,344+2.01 RP
Apr 21, 2026 08:29	Dominique Garmier	CPPclang++19.1.1	Success	8,425
Apr 21, 2026 08:28	Dominique Garmier	CPPclang++20.1.2	Success	8,358+3.71 RP
Apr 21, 2026 08:27	Dominique Garmier	CPPclang++18.1.3	Success	8,448
Apr 21, 2026 08:26	Dominique Garmier	CPPg++13.3.0	Success	24,777
Apr 21, 2026 04:57	Charles Cabergs	CPPg++13.3.0	Success	14,504
Apr 21, 2026 03:20	olliecrow	CPPclang++18.1.3	Success	4,752
Apr 21, 2026 03:15	olliecrow	CPPg++10.5.0	Success	4,938
Apr 21, 2026 01:30	Taylor Dettling	RUSTrust-1.95.0	Success	401,425+24.91 RP
Apr 20, 2026 20:45	Charles Cabergs	CPPg++13.3.0	Success	12,354+25.45 RP
Apr 20, 2026 19:05	olliecrow	CPPclang++18.1.3	Success	5,149
Apr 20, 2026 16:47	Ben	CPPg++13.3.0	Success	27,562+0.08 RP
Apr 20, 2026 16:47	Ben	CPPclang++18.1.3	Success	28,566
Apr 20, 2026 16:47	Ben	CPPclang++18.1.3	Success	27,568+362.74 RP
Apr 20, 2026 16:10	olliecrow	CPPclang++18.1.3	Success	6,430
Apr 20, 2026 15:35	olliecrow	ZIG0.14.0	Success	8,514
Apr 20, 2026 15:31	olliecrow	RUSTrust-1.94.0	Success	13,410
Apr 20, 2026 13:19	Dominique Garmier	CSHARP9.0.15	Success	82,750
Apr 19, 2026 09:11	olliecrow	CPPclang++18.1.3	Success	4,966
Apr 19, 2026 09:09	olliecrow	CPPclang++18.1.3	Success	4,979
Apr 19, 2026 09:04	olliecrow	CPPclang++18.1.3	Success	4,922
Apr 19, 2026 05:11	olliecrow	CPPclang++18.1.3	Success	5,255
Apr 19, 2026 05:07	olliecrow	CPPclang++18.1.3	Success	4,985
Apr 19, 2026 03:33	olliecrow	CPPclang++18.1.3	Success	4,760
Apr 19, 2026 03:28	olliecrow	CPPclang++18.1.3	Success	5,057
Apr 19, 2026 01:00	Charles Cabergs	CPPg++13.3.0	Success	12,755+6.70 RP
Apr 18, 2026 22:43	Charles Cabergs	CPPg++13.3.0	Success	12,865+16.73 RP
Apr 18, 2026 20:27	Charles Cabergs	CPPg++13.3.0	Success	13,148+135.02 RP
Apr 18, 2026 16:07	Charles Cabergs	CPPg++13.3.0	Success	15,986+15.05 RP
Apr 18, 2026 14:23	Charles Cabergs	CPPg++13.3.0	Success	16,832
Apr 18, 2026 04:57	Charles Cabergs	CPPg++13.3.0	Success	16,380+166.37 RP
Apr 18, 2026 01:08	Charles Cabergs	CPPg++13.3.0	Success	22,516+41.45 RP
Apr 17, 2026 23:33	olliecrow	RUSTrust-1.94.0	Success	4,608+19.60 RP
Apr 17, 2026 22:46	olliecrow	RUSTrust-1.94.0	Success	4,767
Apr 17, 2026 22:41	olliecrow	RUSTrust-1.94.0	Success	4,965
Apr 17, 2026 22:29	Charles Cabergs	CPPg++13.3.0	Success	24,834+365.27 RP
Apr 17, 2026 21:05	olliecrow	RUSTrust-1.94.0	Success	13,316
Apr 17, 2026 19:21	Charles Cabergs	CPPg++13.3.0	Success	267,362+37.40 RP
Apr 17, 2026 14:04	olliecrow	RUSTrust-1.94.0	Success	4,679
Apr 17, 2026 13:34	olliecrow	GOgo1.26.1	Success	18,245+170.68 RP
Apr 17, 2026 03:08	olliecrow	RUSTrust-1.94.0	Success	4,768
Apr 17, 2026 03:02	olliecrow	RUSTrust-1.94.0	Error
Apr 17, 2026 02:57	olliecrow	CPPclang++18.1.3	Success	5,383
Apr 17, 2026 02:51	olliecrow	RUSTrust-1.94.0	Success	4,750
Apr 17, 2026 02:49	olliecrow	RUSTrust-1.94.0	Success	4,902
Apr 17, 2026 02:38	olliecrow	RUSTrust-1.94.0	Success	4,766
Apr 17, 2026 02:31	olliecrow	CPPclang++18.1.3	Success	5,315
Apr 17, 2026 02:27	olliecrow	RUSTrust-1.94.0	Success	4,791
Apr 17, 2026 02:19	olliecrow	CPPclang++18.1.3	Success	5,452
Apr 17, 2026 02:15	olliecrow	CPPclang++18.1.3	Success	5,275
Apr 17, 2026 02:15	olliecrow	RUSTrust-1.94.0	Success	4,682
Apr 17, 2026 02:11	olliecrow	RUSTrust-1.94.0	Success	5,338
Apr 17, 2026 02:04	olliecrow	RUSTrust-1.94.0	Success	4,670
Apr 17, 2026 02:00	olliecrow	CPPclang++18.1.3	Error
Apr 17, 2026 01:58	olliecrow	RUSTrust-1.94.0	Success	4,923
Apr 17, 2026 01:51	olliecrow	RUSTrust-1.94.0	Success	4,803
Apr 17, 2026 01:49	olliecrow	CPPclang++18.1.3	Success	6,484
Apr 17, 2026 01:47	olliecrow	RUSTrust-1.94.0	Success	4,829
Apr 17, 2026 01:43	olliecrow	RUSTrust-1.94.0	Success	4,973
Apr 17, 2026 01:43	olliecrow	RUSTrust-1.94.0	Success	4,871
Apr 17, 2026 01:40	olliecrow	RUSTrust-1.94.0	Success	4,764
Apr 17, 2026 01:39	olliecrow	RUSTrust-1.94.0	Success	5,034
Apr 17, 2026 01:37	olliecrow	RUSTrust-1.94.0	Success	4,751
Apr 17, 2026 01:34	olliecrow	RUSTrust-1.94.0	Success	5,794
Apr 17, 2026 01:33	olliecrow	RUSTrust-1.94.0	Success	5,162
Apr 17, 2026 01:28	olliecrow	RUSTrust-1.94.0	Success	4,937
Apr 17, 2026 01:28	olliecrow	RUSTrust-1.94.0	Success	4,927
Apr 17, 2026 01:25	olliecrow	RUSTrust-1.94.0	Success	4,700
Apr 17, 2026 00:11	olliecrow	ZIG0.14.0	Success	90,059
Apr 16, 2026 23:09	olliecrow	CPPclang++18.1.3	Success	5,412
Apr 16, 2026 04:22	olliecrow	CPPclang++18.1.3	Success	6,292
Apr 15, 2026 07:38	olliecrow	RUSTrust-1.94.0	Success	4,764
Apr 15, 2026 06:44	olliecrow	RUSTrust-1.94.0	Success	4,650+21.97 RP
Apr 15, 2026 05:44	olliecrow	RUSTrust-1.94.0	Success	4,698+379.09 RP
Apr 15, 2026 04:56	olliecrow	RUSTrust-1.94.0	Success	35,747
Apr 13, 2026 15:51	limanjun99	CPPg++13.3.0	Success	3,007
Apr 13, 2026 15:50	limanjun99	CPPg++13.3.0	Success	3,006
Apr 13, 2026 15:50	limanjun99	CPPg++13.3.0	Success	3,024
Apr 13, 2026 15:49	limanjun99	CPPg++13.3.0	Success	3,117
Apr 13, 2026 15:39	limanjun99	CPPg++13.3.0	Success	3,010
Apr 13, 2026 15:33	limanjun99	CPPg++13.3.0	Success	3,020
Apr 13, 2026 15:32	limanjun99	CPPg++13.3.0	Success	3,008
Apr 13, 2026 15:32	limanjun99	CPPg++13.3.0	Success	3,013
Apr 13, 2026 15:31	limanjun99	CPPg++13.3.0	Success	3,034
Apr 13, 2026 15:29	limanjun99	CPPg++13.3.0	Success	3,034
Apr 13, 2026 15:28	limanjun99	CPPg++13.3.0	Success	3,034
Apr 13, 2026 15:26	limanjun99	CPPg++13.3.0	Success	2,999+30.84 RP
Apr 13, 2026 15:25	limanjun99	CPPg++13.3.0	Success	3,027+6.54 RP
Apr 13, 2026 15:24	limanjun99	CPPg++13.3.0	Success	3,058
Apr 13, 2026 15:24	limanjun99	CPPg++13.3.0	Success	3,076
Apr 13, 2026 15:09	limanjun99	CPPg++13.3.0	Success	3,050
Apr 13, 2026 15:08	limanjun99	CPPg++13.3.0	Success	3,033+5.43 RP

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