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
Nov 3, 2026 00:46	Andrew Epstein	CSHARP10.0.8	Success	1,263
Nov 3, 2026 00:41	Andrew Epstein	CSHARP10.0.8	Success	1,227+226.03 RP
Nov 3, 2026 00:29	Andrew Epstein	CSHARP10.0.8	Success	1,268
Nov 3, 2026 00:24	Andrew Epstein	CSHARP9.0.18	Success	1,270
Nov 3, 2026 00:17	Andrew Epstein	RUSTrust-1.95.0	Success	1,226
Nov 3, 2026 00:12	Andrew Epstein	RUSTrust-1.95.0	Success	1,165+587.13 RP
Nov 3, 2026 00:09	Andrew Epstein	CSHARP10.0.8	Success	1,262
Nov 2, 2026 23:57	Andrew Epstein	RUSTrust-1.95.0	Success	1,242
Nov 2, 2026 23:57	Andrew Epstein	GOgo1.26.2	Success	1,269+79.91 RP
Nov 2, 2026 23:51	Andrew Epstein	CSHARP10.0.8	Success	1,300
Nov 2, 2026 23:43	Andrew Epstein	RUSTrust-1.95.0	Success	1,252
Nov 2, 2026 23:43	Andrew Epstein	GOgo1.26.2	Success	1,303
Nov 2, 2026 23:43	Andrew Epstein	CPPg++14.2.0	Success	8,091
Nov 2, 2026 23:43	Andrew Epstein	CSHARP10.0.8	Success	1,374
Nov 2, 2026 23:27	Andrew Epstein	ZIG0.15.1	Success	1,224+124.88 RP
Nov 2, 2026 23:26	Andrew Epstein	RUSTrust-1.95.0	Success	1,256
Nov 2, 2026 23:26	Andrew Epstein	GOgo1.26.2	Success	1,304
Nov 2, 2026 22:13	Andrew Epstein	CPPg++14.2.0	Success	1,177+897.82 RP
Nov 2, 2026 22:13	Andrew Epstein	GOgo1.26.2	Success	1,300
Nov 2, 2026 22:13	Andrew Epstein	GOgo1.26.2	Success	1,325
Nov 2, 2026 22:03	Andrew Epstein	GOgo1.26.2	Success	1,303
Nov 2, 2026 21:50	Andrew Epstein	CPPg++14.2.0	Success	8,926
Nov 2, 2026 21:50	Andrew Epstein	CPPclang++20.1.2	Success	8,790
Nov 2, 2026 21:44	Andrew Epstein	CPPg++14.2.0	Success	9,158
Nov 2, 2026 21:41	Andrew Epstein	CPPg++14.2.0	Success	1,389
Nov 2, 2026 21:41	Andrew Epstein	CPPclang++20.1.2	Success	16,399
Nov 2, 2026 21:41	Andrew Epstein	CPPg++14.2.0	Success	16,264
Nov 2, 2026 21:37	Andrew Epstein	CPPg++14.2.0	Success	44,613
Nov 2, 2026 21:34	Andrew Epstein	CPPclang++20.1.2	Success	12,700
Nov 2, 2026 21:34	Andrew Epstein	CPPg++14.2.0	Success	12,762
Nov 2, 2026 21:28	Andrew Epstein	CPPg++14.2.0	Success	1,387
Nov 2, 2026 21:22	Andrew Epstein	CPPclang++20.1.2	Success	24,182
Nov 2, 2026 21:22	Andrew Epstein	CPPg++14.2.0	Success	24,501
Nov 2, 2026 21:20	Andrew Epstein	CPPclang++20.1.2	Success	12,775
Nov 2, 2026 21:20	Andrew Epstein	CPPg++14.2.0	Success	12,735
Nov 2, 2026 21:13	Andrew Epstein	CPPg++14.2.0	Success	24,444
Nov 2, 2026 21:13	Andrew Epstein	CPPclang++20.1.2	Success	24,175
Oct 20, 2026 00:30	highload-churner	CPPg++14.2.0	Success	1,393
Oct 20, 2026 00:27	highload-churner	CPPg++14.2.0	Success	1,409
Oct 20, 2026 00:26	highload-churner	CPPg++14.2.0	Success	1,219
Oct 19, 2026 15:42	highload-churner	CPPg++14.2.0	Success	1,421
Oct 19, 2026 15:41	highload-churner	CPPg++14.2.0	Success	1,191+1'238.36 RP
Oct 19, 2026 15:40	highload-churner	CPPg++14.2.0	Success	1,434
Oct 19, 2026 15:39	highload-churner	CPPg++14.2.0	Error
Oct 19, 2026 15:37	highload-churner	CPPg++14.2.0	Error
Oct 19, 2026 15:31	highload-churner	CPPg++14.2.0	Error
Oct 19, 2026 15:30	highload-churner	CPPg++14.2.0	Error
Oct 19, 2026 15:29	highload-churner	CPPg++14.2.0	Error
Oct 19, 2026 15:11	highload-churner	CPPg++14.2.0	Success	1,432
Oct 19, 2026 15:08	highload-churner	CPPg++14.2.0	Success	1,454
Oct 19, 2026 15:08	highload-churner	CPPg++14.2.0	Success	1,463
Oct 19, 2026 14:57	highload-churner	CPPg++14.2.0	Error
Oct 19, 2026 14:56	highload-churner	CPPg++14.2.0	Error
Oct 19, 2026 14:50	highload-churner	CPPg++14.2.0	Success	1,412
Oct 19, 2026 14:49	highload-churner	CPPg++14.2.0	Success	1,467
Oct 19, 2026 14:48	highload-churner	CPPg++14.2.0	Success	1,409
Oct 19, 2026 14:39	highload-churner	CPPg++14.2.0	Success	1,463
Oct 19, 2026 14:35	highload-churner	CPPg++14.2.0	Success	1,407
Oct 19, 2026 14:34	highload-churner	CPPg++14.2.0	Success	1,458
Oct 19, 2026 14:23	highload-churner	CPPg++14.2.0	Success	1,482
Oct 19, 2026 14:22	highload-churner	CPPg++14.2.0	Success	1,405
Oct 19, 2026 14:12	highload-churner	CPPg++14.2.0	Success	1,448
Oct 19, 2026 14:12	highload-churner	CPPg++14.2.0	Success	1,541
Oct 19, 2026 14:07	highload-churner	CPPg++14.2.0	Success	1,353+165.55 RP
Oct 19, 2026 13:55	highload-churner	CPPg++14.2.0	Success	1,384+198.03 RP
Oct 19, 2026 13:52	highload-churner	CPPg++14.2.0	Success	1,454
Oct 19, 2026 13:41	highload-churner	CPPg++14.2.0	Success	1,547
Oct 19, 2026 13:40	highload-churner	CPPg++14.2.0	Success	1,533
Oct 19, 2026 13:22	highload-churner	CPPg++14.2.0	Success	1,569
Oct 19, 2026 13:20	highload-churner	CPPg++14.2.0	Success	1,566
Oct 19, 2026 13:17	highload-churner	CPPg++14.2.0	Success	1,574
Oct 19, 2026 13:12	highload-churner	CPPg++14.2.0	Success	1,543
Oct 19, 2026 13:11	highload-churner	CPPg++14.2.0	Success	1,550
Oct 19, 2026 13:03	highload-churner	CPPg++14.2.0	Success	1,628
Oct 19, 2026 13:01	highload-churner	CPPg++14.2.0	Success	1,591
Oct 19, 2026 12:57	highload-churner	CPPg++14.2.0	Success	1,423+491.46 RP
Oct 19, 2026 12:56	highload-churner	CPPg++14.2.0	Success	1,576
Oct 19, 2026 12:52	highload-churner	CPPg++14.2.0	Success	1,608
Oct 19, 2026 12:51	highload-churner	CPPg++14.2.0	Success	1,805
Oct 19, 2026 12:51	highload-churner	CPPg++14.2.0	Error
Oct 19, 2026 12:50	highload-churner	CPPg++14.2.0	Error
Oct 19, 2026 12:49	highload-churner	CPPg++14.2.0	Success	1,674
Oct 19, 2026 12:47	highload-churner	CPPg++14.2.0	Success	1,608
Oct 19, 2026 12:43	highload-churner	CPPg++14.2.0	Success	1,530+416.00 RP
Oct 19, 2026 12:39	highload-churner	CPPg++14.2.0	Error
Oct 19, 2026 12:38	highload-churner	CPPg++14.2.0	Error
Oct 19, 2026 12:37	highload-churner	CPPg++14.2.0	Success	1,644
Oct 19, 2026 12:17	highload-churner	CPPg++14.2.0	Error
Oct 19, 2026 12:14	highload-churner	CPPg++14.2.0	Error
Oct 19, 2026 12:11	highload-churner	CPPg++14.2.0	Success	1,634+156.92 RP
Oct 19, 2026 11:43	highload-churner	CPPg++14.2.0	Error
Oct 19, 2026 11:42	highload-churner	CPPg++14.2.0	Error
Oct 19, 2026 11:41	highload-churner	CPPg++14.2.0	Success	1,677+3'016.65 RP
Oct 19, 2026 04:10	zayd-ansari-code	CPPg++10.5.0	Success	1,573,704+6.35 RP
Oct 17, 2026 09:56	Kacpxer	CPPclang++20.1.2	Success	1,619+6'176.65 RP
Oct 17, 2026 07:46	janwww	RUSTrust-1.95.0	Success	1,687
Oct 17, 2026 07:34	janwww	ZIG0.15.1	Success	1,611+197.71 RP
Oct 10, 2026 00:34	highload-churner	CPPg++14.2.0	Success	3,411
Oct 10, 2026 00:32	highload-churner	CPPg++14.2.0	Success	3,394+18.12 RP
Oct 10, 2026 00:31	highload-churner	CPPg++14.2.0	Success	3,598

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