Round 1A: BFFs

1793 correct small sets and 1275 correct large sets. View problem statement or contest analysis.

Compact solutions

Solved in...

C++ (2170 sets)
Python (391 sets)
Java (306 sets)
C# (49 sets)
Ruby (22 sets)
Haskell (21 sets)
C (19 sets)
OCaml (12 sets)
Scala (12 sets)
Go (11 sets)
MATLAB (8 sets)
D (6 sets)
Erlang (4 sets)
JavaScript (4 sets)
Lisp (4 sets)
Pascal (4 sets)
Julia (3 sets)
Kotlin (3 sets)
Perl (3 sets)
Groovy (2 sets)
PHP (2 sets)
Q (2 sets)
Racket (2 sets)
Rust (2 sets)
CJam (1 set)
Factor (1 set)
Picat (1 set)
Visual Basic (1 set)

Submission Origin

China (414 contestants)
United States (240 contestants)
Russia (118 contestants)
Japan (110 contestants)
India (82 contestants)
Taiwan (72 contestants)
Canada (60 contestants)
Brazil (55 contestants)
South Korea (55 contestants)
Australia (34 contestants)
France (33 contestants)
Poland (32 contestants)
Vietnam (31 contestants)
Thailand (28 contestants)
Ukraine (26 contestants)
Bangladesh (22 contestants)
Hong Kong (20 contestants)
Indonesia (20 contestants)
Argentina (19 contestants)
Germany (17 contestants)
Belarus (16 contestants)
Singapore (16 contestants)
Iran (14 contestants)
United Kingdom (13 contestants)
Egypt (12 contestants)
Israel (12 contestants)
Slovakia (12 contestants)
Hungary (10 contestants)
Spain (10 contestants)
Czech Republic (9 contestants)
Kazakhstan (9 contestants)
New Zealand (9 contestants)
Belgium (8 contestants)
Bulgaria (8 contestants)
Greece (8 contestants)
Netherlands (8 contestants)
Romania (8 contestants)
Peru (7 contestants)
Switzerland (7 contestants)
Georgia (6 contestants)
Lithuania (6 contestants)
Mexico (6 contestants)
Portugal (6 contestants)
South Africa (6 contestants)
? (5 contestants)
Bolivia (5 contestants)
Philippines (5 contestants)
Turkey (5 contestants)
Colombia (4 contestants)
Croatia (4 contestants)
Finland (4 contestants)
Slovenia (4 contestants)
Chile (3 contestants)
Iceland (3 contestants)
Serbia (3 contestants)
Sweden (3 contestants)
Turkmenistan (3 contestants)
Denmark (2 contestants)
Dominican Republic (2 contestants)
Kyrgyzstan (2 contestants)
Latvia (2 contestants)
Lebanon (2 contestants)
Moldova (2 contestants)
Austria (1 contestant)
Azerbaijan (1 contestant)
Benin (1 contestant)
Cayman Islands (1 contestant)
Cyprus (1 contestant)
Italy (1 contestant)
Jordan (1 contestant)
Luxembourg (1 contestant)
Macau (1 contestant)
Macedonia (1 contestant)
Malaysia (1 contestant)
Norway (1 contestant)
Paraguay (1 contestant)
Sri Lanka (1 contestant)
Tunisia (1 contestant)
U.S. Virgin Islands (1 contestant)
Venezuela (1 contestant)