Problems from North American Invitational Programming Contest (NAIPC) 2018

	Submissions				Users
Name	Total	Acc.	Ratio	Fastest	Total	Acc.	Ratio	Difficulty
Cut It Out!	162	70	43%	0.03	59	43	73%	5.6
Double Clique	397	109	27%	0.01	107	74	69%	6.5
Flashing Fluorescents	672	225	33%	0.00	162	128	79%	5.5
Missing Gnomes	2997	1121	37%	0.01	741	667	90%	2.5
Prefix Free Code	2206	505	23%	0.04	321	223	69%	6.6
Probe Droids	372	74	20%	0.00	91	47	52%	7.3
Rainbow Graph	155	65	42%	0.01	47	32	68%	5.6
Recovery	1171	357	30%	0.00	243	198	81%	5.3
Red Black Tree	856	357	42%	0.04	166	145	87%	4.6
Winter Festival	47	18	38%	0.07	25	16	64%	6.8
Zoning Houses	1160	358	31%	0.09	248	177	71%	6.4