Problems from 2015 Southeast USA Regionals Division 1

	Submissions				Users
Name	Total	Acc.	Ratio	Fastest	Total	Acc.	Ratio	Difficulty
Airports	486	150	31%	0.11	130	94	72%	6.4
Checkers	203	30	15%	0.00	65	27	42%	7.8
Coverage	125	25	20%	0.04	32	21	66%	7.2
Gears	224	108	48%	0.00	116	102	88%	3.5
Grid	4536	1770	39%	0.01	1249	1086	87%	2.9
Hilbert Sort	265	69	26%	0.04	76	58	76%	7.2
Racing Gems	123	49	40%	0.03	54	40	74%	6.2
Simplicity	2201	882	40%	0.00	845	741	88%	2.5
Weightlifting	152	62	41%	0.00	44	39	89%	5.1