Problems from 2013 ACM-ICPC North American Qualifier

	Submissions				Users
Name	Total	Acc.	Ratio	Fastest	Total	Acc.	Ratio	Difficulty
4 thought	5957	2010	34%	0.00	2001	1666	83%	3.1
Biggest Slice	664	159	24%	0.00	204	127	62%	6.5
Erratic Ants	1142	346	30%	0.00	408	293	72%	4.9
Even Up Solitaire	3845	1340	35%	0.00	1236	999	81%	2.7
Goldbach's Conjecture	3354	1247	37%	0.00	1216	955	79%	3.5
Island Buses	437	127	29%	0.00	133	96	72%	5.9
Oddities	17272	9841	57%	0.00	8810	8517	97%	1.2
Plotting Polynomials	236	182	77%	0.00	185	168	91%	2.4
Shotcube	255	42	16%	0.17	63	27	43%	7.6
Ternarian Weights	594	230	39%	0.00	264	217	82%	3.9
Trapezoid Walkway	382	191	50%	0.00	191	166	87%	3.3