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
Dec 29, 2025 15:57	Josu San Martin	RUSTrust-1.92.0	Error
Dec 29, 2025 15:57	Josu San Martin	RUSTrust-1.92.0	Error
Dec 29, 2025 15:57	Josu San Martin	RUSTrust-1.92.0	Success	27,462
Dec 29, 2025 15:57	Josu San Martin	RUSTrust-1.92.0	Error
Dec 29, 2025 15:57	Josu San Martin	RUSTrust-1.92.0	Success	27,460
Dec 29, 2025 15:57	Josu San Martin	RUSTrust-1.92.0	Success	27,440
Dec 29, 2025 15:57	Josu San Martin	RUSTrust-1.92.0	Error
Dec 29, 2025 15:57	Josu San Martin	RUSTrust-1.92.0	Error
Dec 29, 2025 15:56	Josu San Martin	RUSTrust-1.92.0	Success	27,559
Dec 29, 2025 15:56	Josu San Martin	RUSTrust-1.92.0	Success	27,446
Dec 29, 2025 15:55	Josu San Martin	RUSTrust-1.92.0	Success	27,663
Dec 29, 2025 15:54	Josu San Martin	RUSTrust-1.92.0	Error
Dec 29, 2025 15:52	Josu San Martin	RUSTrust-1.92.0	Error
Dec 29, 2025 14:54	Josu San Martin	RUSTrust-1.92.0	Success	27,419+3.99 RP
Dec 29, 2025 14:40	Josu San Martin	RUSTrust-1.92.0	Success	27,722+1.85 RP
Dec 29, 2025 14:39	Josu San Martin	RUSTrust-1.92.0	Error
Dec 23, 2025 07:07	AnSa	CPPg++13.3.0	Success	1,119,423+0.14 RP
Dec 23, 2025 06:48	AnSa	CPPg++13.3.0	Success	1,168,522
Dec 23, 2025 06:46	AnSa	CPPg++13.3.0	Success	1,168,966
Dec 23, 2025 06:40	AnSa	CPPg++13.3.0	Error
Dec 23, 2025 06:34	AnSa	CPPg++13.3.0	Error
Dec 23, 2025 05:45	Josu San Martin	CPPclang++18.1.3	Success	31,803
Dec 23, 2025 05:44	Josu San Martin	CPPclang++18.1.3	Success	31,774
Dec 23, 2025 05:44	Josu San Martin	CPPg++13.3.0	Success	51,621
Dec 23, 2025 05:25	Josu San Martin	RUSTrust-1.92.0	Success	28,030
Dec 23, 2025 05:17	Josu San Martin	RUSTrust-1.92.0	Success	30,741
Dec 23, 2025 05:00	Josu San Martin	RUSTrust-1.92.0	Success	27,865+46.41 RP
Dec 23, 2025 04:58	Josu San Martin	CPPclang++18.1.3	Success	71,225
Dec 23, 2025 04:58	Josu San Martin	CPPclang++18.1.3	Success	32,004+117.84 RP
Dec 23, 2025 04:58	Josu San Martin	CPPclang++18.1.3	Error
Dec 23, 2025 04:57	Josu San Martin	CPPg++13.3.0	Success	51,381+0.56 RP
Dec 23, 2025 04:55	Josu San Martin	CPPg++13.3.0	Success	51,529+11.34 RP
Dec 23, 2025 04:55	Josu San Martin	CPPg++13.3.0	Error
Dec 23, 2025 04:48	Josu San Martin	CPPg++13.3.0	Success	54,726+48.46 RP
Dec 23, 2025 04:48	Josu San Martin	RUSTrust-1.92.0	Success	74,478+95.08 RP
Dec 23, 2025 04:43	Josu San Martin	RUSTrust-1.92.0	Success	290,740
Dec 23, 2025 04:43	Josu San Martin	CPPg++13.3.0	Success	255,203+39.18 RP
Dec 23, 2025 04:36	Josu San Martin	CPPg++13.3.0	Error
Dec 23, 2025 04:30	Josu San Martin	RUSTrust-1.92.0	Error
Dec 22, 2025 18:01	Josu San Martin	CPPg++13.3.0	Error
Nov 18, 2025 22:20	Yuriy Lyfenko	CPPclang++18.1.3	Success	4,134
Nov 18, 2025 22:06	Yuriy Lyfenko	CPPg++13.3.0	Success	4,027
Nov 18, 2025 22:05	Yuriy Lyfenko	CPPclang++18.1.3	Success	4,047
Nov 18, 2025 22:04	Yuriy Lyfenko	CPPg++13.3.0	Success	4,014+12.35 RP
Nov 18, 2025 22:01	Yuriy Lyfenko	CPPg++13.3.0	Success	4,052
Nov 18, 2025 21:56	Yuriy Lyfenko	CPPg++13.3.0	Success	4,042
Nov 18, 2025 21:55	Yuriy Lyfenko	CPPg++13.3.0	Success	4,034+16.48 RP
Nov 18, 2025 21:08	Yuriy Lyfenko	CPPg++13.3.0	Success	4,061+2'060.23 RP
Nov 18, 2025 18:56	Yuriy Lyfenko	CPPg++13.3.0	Error
Nov 18, 2025 18:53	Yuriy Lyfenko	CPPg++13.3.0	Error
Nov 18, 2025 18:44	Yuriy Lyfenko	CPPg++13.3.0	Error
Nov 18, 2025 18:38	Yuriy Lyfenko	CPPg++13.3.0	Error
Nov 18, 2025 18:31	Yuriy Lyfenko	CPPg++13.3.0	Error
Nov 18, 2025 18:28	Yuriy Lyfenko	CPPg++13.3.0	Error
Nov 18, 2025 18:16	Yuriy Lyfenko	CPPg++13.3.0	Error
Nov 18, 2025 18:13	Yuriy Lyfenko	CPPg++13.3.0	Error
Nov 18, 2025 18:10	Yuriy Lyfenko	CPPg++13.3.0	Error
Nov 18, 2025 18:00	Yuriy Lyfenko	CPPg++13.3.0	Error
Nov 18, 2025 17:55	Yuriy Lyfenko	CPPg++13.3.0	Error
Nov 18, 2025 17:53	Yuriy Lyfenko	CPPg++13.3.0	Error
Nov 18, 2025 17:41	Yuriy Lyfenko	CPPg++13.3.0	Error
Nov 17, 2025 17:14	Yuriy Lyfenko	CPPg++13.3.0	Success	24,966
Nov 17, 2025 17:11	Yuriy Lyfenko	CPPg++13.3.0	Success	25,016
Nov 17, 2025 17:09	Yuriy Lyfenko	CPPg++13.3.0	Success	24,902
Nov 17, 2025 16:44	Yuriy Lyfenko	CPPg++13.3.0	Success	24,862+0.50 RP
Nov 17, 2025 06:58	Yuriy Lyfenko	CPPg++13.3.0	Success	24,929
Nov 17, 2025 06:57	Yuriy Lyfenko	CPPg++13.3.0	Success	24,893+144.83 RP
Nov 17, 2025 06:52	Yuriy Lyfenko	CPPg++13.3.0	Error
Nov 17, 2025 06:35	Yuriy Lyfenko	CPPg++13.3.0	Error
Nov 17, 2025 06:30	Yuriy Lyfenko	CPPg++13.3.0	Error
Nov 17, 2025 06:21	Yuriy Lyfenko	CPPg++13.3.0	Success	39,057
Nov 17, 2025 06:13	Yuriy Lyfenko	CPPg++13.3.0	Success	38,928+0.74 RP
Nov 17, 2025 06:13	Yuriy Lyfenko	CPPg++13.3.0	Success	42,722
Nov 17, 2025 06:12	Yuriy Lyfenko	CPPclang++18.1.3	Success	40,731
Nov 17, 2025 06:12	Yuriy Lyfenko	CPPg++13.3.0	Success	39,040+5.71 RP
Nov 17, 2025 06:04	Yuriy Lyfenko	CPPg++13.3.0	Success	39,930+3.82 RP
Nov 17, 2025 06:02	Yuriy Lyfenko	CPPg++13.3.0	Success	40,616
Nov 17, 2025 05:47	Yuriy Lyfenko	CPPg++13.3.0	Success	40,549+0.75 RP
Nov 17, 2025 05:33	Yuriy Lyfenko	CPPg++13.3.0	Success	40,673+51.59 RP
Nov 17, 2025 05:31	Yuriy Lyfenko	CPPg++13.3.0	Success	51,474+12.40 RP
Nov 17, 2025 05:10	Yuriy Lyfenko	CPPg++13.3.0	Error
Nov 17, 2025 05:10	Yuriy Lyfenko	CPPg++13.3.0	Error
Nov 17, 2025 05:08	Yuriy Lyfenko	CPPg++13.3.0	Error
Nov 17, 2025 05:05	Yuriy Lyfenko	CPPg++13.3.0	Error
Nov 16, 2025 14:04	Aniruddha Deb	CPPg++13.3.0	Success	6,212+13.87 RP
Nov 16, 2025 13:58	Aniruddha Deb	CPPg++13.3.0	Success	8,743
Nov 16, 2025 13:56	Aniruddha Deb	CPPg++13.3.0	Success	8,790
Nov 14, 2025 17:54	izotoff	GOgo1.21.5	Success	33,933+7.02 RP
Nov 14, 2025 17:52	izotoff	GOgo1.25.4	Success	34,774
Nov 14, 2025 17:47	izotoff	GOgo1.25.4	Success	34,779
Nov 14, 2025 17:34	izotoff	GOgo1.25.4	Success	34,778
Nov 14, 2025 17:19	izotoff	GOgo1.25.4	Success	34,761+0.49 RP
Nov 14, 2025 17:06	izotoff	GOgo1.25.4	Success	35,064
Nov 14, 2025 16:39	izotoff	GOgo1.25.4	Success	34,820+287.19 RP
Nov 12, 2025 14:05	Yehor Bondar	CPPg++13.3.0	Success	377,176+26.51 RP
Jul 29, 2025 21:00	Aniruddha Deb	CPPg++13.3.0	Error
Jul 20, 2025 05:45	T Pratham	CPPg++13.3.0	Success	338,760+2.86 RP
Jul 7, 2025 23:09	Aniruddha Deb	CPPg++13.3.0	Success	6,274
Jul 6, 2025 19:07	T Pratham	CPPg++13.3.0	Success	375,149+2.33 RP
Jul 6, 2025 19:00	T Pratham	CPPg++13.3.0	Success	411,070+0.02 RP

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