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 14, 2026 22:27	Elijah Kin	CPPclang++18.1.3	Success	496,627
Mar 14, 2026 22:20	Elijah Kin	CPPclang++18.1.3	Success	496,708+12.20 RP
Mar 14, 2026 22:01	Elijah Kin	CPPclang++18.1.3	Success	1,260,994+7.93 RP
Mar 14, 2026 18:54	Dominique Garmier	CPPg++13.3.0	Success	30,462+186.90 RP
Mar 14, 2026 18:29	Dominique Garmier	CPPg++13.3.0	Success	70,733+0.03 RP
Mar 14, 2026 18:26	Dominique Garmier	CPPg++13.3.0	Success	70,748+119.21 RP
Mar 14, 2026 16:11	Dominique Garmier	CPPg++13.3.0	Error
Mar 14, 2026 15:59	Dominique Garmier	CPPclang++18.1.3	Success	488,385
Mar 14, 2026 15:58	Dominique Garmier	CPPg++13.3.0	Success	451,714
Mar 14, 2026 15:57	Dominique Garmier	CPPclang++18.1.3	Success	488,308
Mar 14, 2026 11:14	Keefe	CPPclang++18.1.3	Success	3,799+2.08 RP
Mar 14, 2026 11:08	Dominique Garmier	CPPg++13.3.0	Success	451,684+0.01 RP
Mar 14, 2026 11:03	Dominique Garmier	CPPg++13.3.0	Success	451,790+13.35 RP
Mar 14, 2026 08:09	Keefe	CPPclang++18.1.3	Success	3,802+424.64 RP
Mar 14, 2026 08:08	Keefe	CPPg++13.3.0	Success	4,534+1'573.21 RP
Mar 13, 2026 11:41	Dominique Garmier	CPPg++13.3.0	Success	1,138,191+8.79 RP
Mar 12, 2026 03:40	olliecrow	RUSTrust-1.87.0	Success	8,613+6.43 RP
Mar 12, 2026 03:31	olliecrow	RUSTrust-1.88.0	Success	8,661+1.20 RP
Mar 12, 2026 03:20	olliecrow	RUSTrust-1.88.0	Success	8,698
Mar 12, 2026 03:14	olliecrow	RUSTrust-1.88.0	Success	8,764
Mar 12, 2026 03:09	olliecrow	CPPclang++18.1.3	Success	9,164
Mar 12, 2026 03:01	olliecrow	RUSTrust-1.88.0	Success	10,774
Mar 12, 2026 02:58	olliecrow	CPPclang++18.1.3	Success	9,712
Mar 12, 2026 02:47	olliecrow	RUSTrust-1.87.0	Success	8,680
Mar 12, 2026 02:38	olliecrow	RUSTrust-1.88.0	Success	8,670+15.75 RP
Mar 12, 2026 02:36	olliecrow	CPPclang++18.1.3	Success	9,443
Mar 12, 2026 02:31	olliecrow	RUSTrust-1.94.0	Success	8,790+78.11 RP
Mar 12, 2026 02:30	olliecrow	CPPclang++18.1.3	Success	9,438+171.60 RP
Mar 10, 2026 11:40	izotoff	GOgo1.26.1	Error
Mar 10, 2026 11:37	izotoff	GOgo1.26.1	Success	34,622
Mar 10, 2026 11:36	izotoff	GOgo1.21.5	Error
Mar 10, 2026 05:07	olliecrow	CPPg++13.3.0	Success	21,409
Mar 10, 2026 05:05	olliecrow	CPPclang++18.1.3	Success	11,262+0.47 RP
Mar 10, 2026 05:03	olliecrow	CPPclang++18.1.3	Success	11,372
Mar 10, 2026 05:01	olliecrow	CPPclang++18.1.3	Success	11,268+174.61 RP
Mar 4, 2026 20:21	olliecrow	CPPg++13.3.0	Success	25,207
Mar 4, 2026 20:17	olliecrow	CPPg++13.3.0	Error
Mar 4, 2026 20:13	olliecrow	CPPg++13.3.0	Error
Mar 4, 2026 20:06	olliecrow	CPPclang++18.1.3	Success	14,055
Mar 4, 2026 19:59	olliecrow	CPPclang++18.1.3	Success	14,346
Mar 4, 2026 19:55	olliecrow	CPPclang++18.1.3	Success	14,108
Mar 4, 2026 19:39	olliecrow	CPPg++13.3.0	Success	15,917
Mar 4, 2026 19:36	olliecrow	CPPclang++18.1.3	Success	14,028+5.00 RP
Mar 4, 2026 19:32	olliecrow	CPPclang++18.1.3	Success	15,040
Mar 4, 2026 19:23	olliecrow	CPPclang++18.1.3	Success	14,127+11.19 RP
Mar 4, 2026 19:20	olliecrow	CPPclang++18.1.3	Success	14,354+80.79 RP
Mar 4, 2026 19:16	olliecrow	CPPclang++18.1.3	Success	16,263
Mar 4, 2026 19:12	olliecrow	CPPclang++18.1.3	Success	16,237+68.11 RP
Mar 4, 2026 19:07	olliecrow	CPPclang++18.1.3	Success	18,354
Mar 4, 2026 19:04	olliecrow	CPPclang++18.1.3	Success	18,330
Mar 4, 2026 19:01	olliecrow	CPPclang++18.1.3	Success	18,256+4.23 RP
Mar 4, 2026 18:57	olliecrow	CPPclang++18.1.3	Success	18,398+0.77 RP
Mar 4, 2026 18:53	olliecrow	CPPclang++18.1.3	Success	18,800
Mar 4, 2026 18:49	olliecrow	CPPclang++18.1.3	Success	18,812
Mar 4, 2026 18:38	olliecrow	CPPclang++18.1.3	Success	18,471
Mar 4, 2026 18:34	olliecrow	CPPclang++18.1.3	Success	18,424+132.45 RP
Mar 4, 2026 18:28	olliecrow	CPPclang++18.1.3	Success	24,981
Mar 4, 2026 18:27	olliecrow	CPPclang++18.1.3	Success	24,618
Mar 4, 2026 18:26	olliecrow	CPPclang++18.1.3	Success	24,450
Mar 4, 2026 18:24	olliecrow	CPPg++13.3.0	Error
Mar 4, 2026 18:21	olliecrow	CPPg++13.3.0	Success	41,213
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

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