Largest Square Submatrix of all 1's

Find the largest square submatrix consisting entirely of 1s as fast as possible.

Input

A 10,000 x 10,000 matrix of uint8 values (0 or 1) on STDIN.

0, 1, 0, 1, 1
0, 1, 1, 1, 1
0, 0, 1, 0, 0
1, 0, 1, 1, 0

Output

Print the side length of the largest all-ones square submatrix to STDOUT. The answer is guaranteed to be greater than 1.

For the example above, the output is:

Restrictions:60s256Mb 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.

Back to listMar 14, 2026 19:04

Dominique Garmier

Score: 192,620

Success

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Run Statistics

#	Date	Score	Wall Time	CPU User	CPU System	Memory
1	Mar 14, 2026 19:09	181,188	93,188,123	58,383,000	14,092,000	2,519,040
2	Mar 14, 2026 19:09	181,255	105,340,759	58,405,000	14,097,000	2,510,848
3	Mar 14, 2026 19:09	181,613	100,315,736	59,529,000	13,116,000	2,260,992
4	Mar 14, 2026 18:36	181,960	106,122,509	60,820,000	11,964,000	2,519,040
5	Mar 14, 2026 19:04	182,365	102,508,763	58,957,000	13,989,000	2,269,184
6	Mar 14, 2026 18:54	184,358	103,064,013	57,799,000	15,944,000	2,519,040
7	Mar 14, 2026 19:09	185,175	105,513,515	59,056,000	15,014,000	2,519,040
8	Mar 14, 2026 19:09	185,615	97,601,978	61,203,000	13,043,000	2,473,984
9	Mar 14, 2026 18:36	185,728	98,027,528	63,248,000	11,043,000	2,269,184
10	Mar 14, 2026 18:47	187,280	100,916,239	59,930,000	14,982,000	2,265,088
11	Mar 14, 2026 18:54	188,563	100,379,472	64,363,000	11,062,000	2,519,040
12	Mar 14, 2026 18:45	188,780	108,319,475	62,424,000	13,088,000	2,510,848
13	Mar 14, 2026 18:36	189,153	102,847,167	61,538,000	14,123,000	2,260,992
14	Mar 14, 2026 19:09	190,010	105,586,157	65,004,000	11,000,000	2,510,848
15	Mar 14, 2026 18:50	190,128	99,686,614	63,043,000	13,008,000	2,269,184
16	Mar 14, 2026 18:54	190,298	104,105,313	65,102,000	11,017,000	2,269,184
17	Mar 14, 2026 18:47	191,305	104,818,158	63,433,000	13,089,000	2,269,184
18	Mar 14, 2026 18:54	191,495	108,470,568	65,512,000	11,086,000	2,269,184
19	Mar 14, 2026 18:36	191,880	115,386,401	65,788,000	10,964,000	2,457,600
20	Mar 14, 2026 18:36	192,285	104,453,988	65,927,000	10,987,000	2,519,040
21	Mar 14, 2026 18:45	192,358	108,579,511	62,954,000	13,989,000	2,318,336
22	Mar 14, 2026 18:54	192,620	107,215,428	64,040,000	13,008,000	2,269,184
23	Mar 14, 2026 19:16	193,755	107,177,419	67,437,000	10,065,000	2,265,088
24	Mar 14, 2026 19:16	194,420	107,489,275	64,807,000	12,961,000	2,269,184
25	Mar 14, 2026 18:50	194,768	108,197,387	69,917,000	7,990,000	2,519,040
26	Mar 14, 2026 18:54	194,800	111,439,037	65,933,000	11,987,000	2,260,992
27	Mar 14, 2026 18:54	194,875	103,924,489	66,957,000	10,993,000	2,265,088
28	Mar 14, 2026 18:36	194,973	110,294,212	64,991,000	12,998,000	2,297,856
29	Mar 14, 2026 19:09	195,078	111,902,671	63,025,000	15,006,000	2,260,992
30	Mar 14, 2026 18:36	195,195	105,532,159	68,068,000	10,010,000	2,318,336
31	Mar 14, 2026 18:54	195,525	107,798,873	67,181,000	11,029,000	2,269,184
32	Mar 14, 2026 18:36	195,650	111,363,041	67,224,000	11,036,000	2,269,184
33	Mar 14, 2026 18:47	196,035	104,076,848	64,340,000	14,074,000	2,269,184
34	Mar 14, 2026 18:50	196,375	110,874,868	67,473,000	11,077,000	2,519,040
35	Mar 14, 2026 19:04	197,008	103,190,693	66,833,000	11,970,000	2,510,848
36	Mar 14, 2026 19:09	197,083	111,159,174	63,865,000	14,968,000	2,269,184
37	Mar 14, 2026 18:45	198,580	104,158,002	68,372,000	11,060,000	2,519,040
38	Mar 14, 2026 18:54	198,615	107,233,133	66,373,000	13,073,000	2,363,392
39	Mar 14, 2026 19:04	203,608	108,900,465	71,389,000	10,054,000	2,519,040
40	Mar 14, 2026 19:09	209,090	117,262,254	69,529,000	14,107,000	2,269,184
41	Mar 14, 2026 18:36	210,690	108,824,610	71,234,000	13,042,000	2,510,848
42	Mar 14, 2026 19:16	210,843	114,224,163	71,285,000	13,052,000	2,260,992

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