Problems from 2013 ACM-ICPC North American Qualifier

	Submissions				Users
Name	Total	Acc.	Ratio	Fastest	Total	Acc.	Ratio	Difficulty
4 thought	12712	4363	34%	0.00	4156	3502	84%	2.9
Biggest Slice	997	249	25%	0.00	282	181	64%	6.3
Erratic Ants	1560	472	30%	0.00	543	402	74%	5.0
Even Up Solitaire	6336	2525	40%	0.00	2219	1870	84%	2.6
Goldbach's Conjecture	4819	1915	40%	0.00	1802	1490	83%	2.7
Island Buses	625	177	28%	0.00	204	137	67%	7.3
Oddities	32571	17610	54%	0.00	15550	14953	96%	1.5
Plotting Polynomials	370	295	80%	0.00	280	261	93%	2.4
Shotcube	376	61	16%	0.17	81	37	46%	8.4
Ternarian Weights	839	348	41%	0.00	364	303	83%	3.8
Trapezoid Walkway	538	260	48%	0.00	260	226	87%	3.5