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
Mar 4, 2026 18:16	olliecrow	CPPclang++18.1.3	Success	24,657
Mar 4, 2026 18:12	olliecrow	CPPg++13.3.0	Success	41,477
Mar 4, 2026 18:09	olliecrow	CPPg++13.3.0	Success	34,962
Mar 4, 2026 18:05	olliecrow	CPPclang++18.1.3	Success	25,138
Mar 4, 2026 18:02	olliecrow	CPPg++13.3.0	Success	24,629
Mar 4, 2026 17:58	olliecrow	CPPclang++18.1.3	Success	24,371+410.32 RP
Feb 7, 2026 21:50	T Pratham	CPPg++13.3.0	Success	8,985
Feb 7, 2026 21:34	T Pratham	CPPg++13.3.0	Success	9,319
Feb 7, 2026 21:14	T Pratham	CPPg++13.3.0	Success	8,736+194.39 RP
Feb 7, 2026 20:59	T Pratham	CPPg++13.3.0	Success	10,523+6.19 RP
Feb 7, 2026 20:53	T Pratham	CPPg++13.3.0	Success	11,026
Feb 7, 2026 20:45	T Pratham	CPPg++13.3.0	Success	10,592+609.15 RP
Feb 7, 2026 18:43	T Pratham	CPPg++13.3.0	Success	29,854+305.44 RP
Feb 6, 2026 16:10	Josu San Martin	CPPclang++18.1.3	Success	3,019
Feb 6, 2026 15:29	Josu San Martin	CPPclang++18.1.3	Success	2,950+95.16 RP
Feb 6, 2026 06:16	Josu San Martin	RUSTrust-1.92.0	Success	3,678
Feb 6, 2026 06:05	Josu San Martin	RUSTrust-1.92.0	Success	3,563+1'814.56 RP
Feb 6, 2026 06:04	Josu San Martin	RUSTrust-1.92.0	Error
Feb 6, 2026 06:02	Josu San Martin	CPPclang++18.1.3	Success	2,992+88.18 RP
Feb 6, 2026 05:19	Josu San Martin	CPPclang++18.1.3	Success	3,166
Feb 6, 2026 05:19	Josu San Martin	CPPclang++18.1.3	Success	3,104
Feb 6, 2026 05:07	Josu San Martin	CPPclang++18.1.3	Success	3,032+1'424.74 RP
Feb 6, 2026 04:42	Josu San Martin	CPPclang++18.1.3	Success	4,619
Feb 6, 2026 04:41	Josu San Martin	CPPclang++18.1.3	Success	4,598+7.54 RP
Feb 6, 2026 02:17	Josu San Martin	CPPclang++18.1.3	Success	4,614+257.83 RP
Feb 6, 2026 01:42	Josu San Martin	CPPclang++18.1.3	Success	5,237+13.04 RP
Feb 6, 2026 01:41	Josu San Martin	CPPclang++18.1.3	Success	5,456
Feb 6, 2026 01:40	Josu San Martin	CPPclang++18.1.3	Success	5,794
Feb 6, 2026 01:36	Josu San Martin	CPPclang++18.1.3	Success	5,370
Feb 6, 2026 00:50	Josu San Martin	CPPclang++18.1.3	Success	5,650
Feb 5, 2026 23:10	Josu San Martin	CPPclang++18.1.3	Success	5,723
Feb 5, 2026 22:17	Josu San Martin	CPPclang++18.1.3	Success	5,306
Feb 5, 2026 14:32	Josu San Martin	CPPclang++18.1.3	Success	5,273+34.26 RP
Feb 5, 2026 05:18	Josu San Martin	CPPclang++18.1.3	Success	5,370+21.59 RP
Feb 5, 2026 05:02	Josu San Martin	CPPclang++18.1.3	Success	5,472
Feb 5, 2026 04:46	Josu San Martin	CPPclang++18.1.3	Success	5,433+14.45 RP
Feb 5, 2026 04:46	Josu San Martin	CPPclang++18.1.3	Success	5,637
Feb 5, 2026 04:45	Josu San Martin	CPPclang++18.1.3	Success	5,572
Feb 5, 2026 04:45	Josu San Martin	CPPclang++18.1.3	Success	5,476+3.99 RP
Feb 5, 2026 04:15	Josu San Martin	CPPclang++18.1.3	Success	5,565
Feb 5, 2026 04:08	Josu San Martin	CPPclang++18.1.3	Success	5,488+25.86 RP
Feb 5, 2026 03:55	Josu San Martin	CPPclang++18.1.3	Success	5,777
Feb 5, 2026 03:44	Josu San Martin	CPPclang++18.1.3	Success	5,567+71.27 RP
Feb 5, 2026 03:43	Josu San Martin	CPPg++13.3.0	Success	6,764
Feb 5, 2026 03:43	Josu San Martin	CPPclang++18.1.3	Success	5,797+331.50 RP
Feb 5, 2026 03:43	Josu San Martin	CPPg++13.3.0	Success	7,176+99.20 RP
Feb 5, 2026 03:38	Josu San Martin	CPPg++13.3.0	Success	7,726+111.18 RP
Feb 5, 2026 02:51	Josu San Martin	CPPg++13.3.0	Success	8,452+32.93 RP
Jan 16, 2026 19:42	Josu San Martin	CPPg++13.3.0	Success	9,635
Jan 16, 2026 04:03	Josu San Martin	CPPg++13.3.0	Success	9,837
Jan 16, 2026 03:48	Josu San Martin	CPPg++13.3.0	Success	8,694+105.18 RP
Jan 16, 2026 03:31	Josu San Martin	CPPg++13.3.0	Success	9,977
Jan 16, 2026 03:31	Josu San Martin	CPPg++13.3.0	Success	9,768
Jan 16, 2026 03:27	Josu San Martin	CPPg++13.3.0	Success	9,990
Jan 16, 2026 03:20	Josu San Martin	CPPg++13.3.0	Success	9,684
Jan 16, 2026 03:18	Josu San Martin	CPPg++13.3.0	Success	9,569+52.98 RP
Jan 16, 2026 03:03	Josu San Martin	CPPg++13.3.0	Success	15,249
Jan 16, 2026 03:00	Josu San Martin	RUSTrust-1.92.0	Success	13,360
Jan 16, 2026 02:53	Josu San Martin	CPPg++13.3.0	Success	11,867
Jan 16, 2026 02:37	Josu San Martin	CPPg++13.3.0	Success	12,364
Jan 16, 2026 02:36	Josu San Martin	RUSTrust-1.92.0	Success	10,080+39.36 RP
Jan 7, 2026 02:55	Josu San Martin	CPPg++13.3.0	Success	12,356
Jan 7, 2026 02:52	Josu San Martin	GOgo1.25.5	Success	27,690
Jan 5, 2026 02:38	Josu San Martin	CPPclang++18.1.3	Success	11,394
Jan 5, 2026 02:38	Josu San Martin	CPPclang++18.1.3	Error
Jan 5, 2026 02:29	Josu San Martin	CPPclang++18.1.3	Error
Jan 4, 2026 17:54	Josu San Martin	CPPclang++18.1.3	Error
Jan 4, 2026 04:14	Josu San Martin	RUSTrust-1.92.0	Success	10,284+97.01 RP
Jan 1, 2026 23:38	Josu San Martin	CPPclang++18.1.3	Success	11,606
Jan 1, 2026 22:18	Josu San Martin	CPPclang++18.1.3	Success	13,761
Jan 1, 2026 22:18	Josu San Martin	CPPclang++18.1.3	Error
Jan 1, 2026 22:17	Josu San Martin	CPPclang++18.1.3	Success	18,528
Jan 1, 2026 22:17	Josu San Martin	CPPclang++18.1.3	Success	18,300
Jan 1, 2026 22:17	Josu San Martin	CPPclang++18.1.3	Success	14,648
Jan 1, 2026 22:06	Josu San Martin	CPPclang++18.1.3	Success	43,220
Jan 1, 2026 21:43	Josu San Martin	CPPclang++18.1.3	Success	10,388+72.97 RP
Jan 1, 2026 21:30	Josu San Martin	RUSTrust-1.92.0	Success	13,178
Jan 1, 2026 21:25	Josu San Martin	CPPclang++18.1.3	Success	11,240+4.57 RP
Jan 1, 2026 21:23	Josu San Martin	CPPclang++18.1.3	Error
Jan 1, 2026 21:20	Josu San Martin	CPPclang++18.1.3	Error
Jan 1, 2026 21:15	Josu San Martin	RUSTrust-1.92.0	Success	11,298+351.62 RP
Jan 1, 2026 20:57	Josu San Martin	CPPclang++18.1.3	Success	11,741+284.82 RP
Jan 1, 2026 20:54	Josu San Martin	CPPclang++18.1.3	Error
Jan 1, 2026 19:40	Josu San Martin	CPPclang++18.1.3	Success	50,149
Jan 1, 2026 19:17	Josu San Martin	CPPclang++18.1.3	Success	18,368
Jan 1, 2026 18:50	Josu San Martin	CPPclang++18.1.3	Success	18,532
Jan 1, 2026 17:16	Josu San Martin	CPPclang++18.1.3	Error
Jan 1, 2026 17:14	Josu San Martin	CPPclang++18.1.3	Success	19,449
Jan 1, 2026 16:39	Josu San Martin	CPPg++13.3.0	Success	30,517
Dec 30, 2025 23:26	Aniruddha Deb	CPPg++13.3.0	Success	3,337+30.38 RP
Dec 30, 2025 23:25	Aniruddha Deb	CPPg++13.3.0	Success	3,376
Dec 30, 2025 23:24	Aniruddha Deb	CPPg++13.3.0	Success	3,370
Dec 30, 2025 23:22	Aniruddha Deb	CPPg++13.3.0	Success	3,354+61.58 RP
Dec 30, 2025 22:46	Aniruddha Deb	CPPg++13.3.0	Success	3,626
Dec 30, 2025 22:35	Aniruddha Deb	CPPg++13.3.0	Success	3,773
Dec 30, 2025 22:25	Aniruddha Deb	CPPg++13.3.0	Success	3,789
Dec 30, 2025 22:14	Aniruddha Deb	CPPg++13.3.0	Success	3,389+712.04 RP
Dec 30, 2025 22:04	Aniruddha Deb	CPPg++13.3.0	Success	3,854+1'004.96 RP
Dec 30, 2025 05:56	Josu San Martin	GOgo1.25.5	Success	62,623
Dec 30, 2025 05:50	Josu San Martin	GOgo1.25.5	Success	61,934

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