Sphere Online Judge (SPOJ)

list of classical problems

ID	NAME	USERS	ACC %	DIFFICULTY C I
2631	Chomp	108	45.91
2643	Starcraft I	54	22.25
2658	Art of War	17	17.65
2661	Illumination	6	3.40
2662	Put a Point in a Hyperspace	17	11.06
2709	Untitled Problem	27	17.75
2733	K Equal Digits	10	11.96
2734	Large party	34	24.35
2735	Simplify the Railroad System	56	36.02	17 1
2855	Forest	57	12.20
2877	Another understanding of Super Dice Game	64	10.00
2879	The Cow Doctor	141	37.24	17
2880	Wild West	99	42.47	17 34
2898	Party of Cloaked Killers	29	21.15
2899	Volunteers	55	46.91	17 34
2902	Candy IV	31	51.25	50 34
2903	Transportation	11	46.43
2940	Untitled Problem II	116	15.17	34
2944	Emmons	7	8.28
2962	Painting Blocks (Act I)	107	58.24
3002	Electrophoretic	12	26.00
3005	Subdividing a Land	24	37.80
3009	Revenge of Voronoi	14	35.26
3010	Castle Wall	25	22.13
3078	Copying DNA	44	23.53
3108	Charlesbert and Merangelou	71	47.31
3166	Permutation Exponentiation	33	14.85
3197	Tree Construction	62	20.00
3208	Yet Another Longest Palindrome Problem	68	13.65
3251	Slink	15	44.44	1 1
3254	Guard	14	51.72
3305	Roman Patrollers	45	59.26
3309	Bulletin Board	19	20.80
3314	Umnozak	102	29.03	42 17
3347	Cestarine	59	34.58
3359	Stack	45	15.60
3360	Digital Image Recognition	25	8.19
3373	Permutation Code	41	55.70
3393	Knot or Not	6	13.56
3406	Bases	68	21.12
3412	Higgs Boson	48	18.93
3414	Bora Bora	144	48.65	34 26
3415	Shrinking Polygons	230	18.87
3420	Falling Ice	7	24.14
3461	Song Contest	12	14.44
3462	The Skatepark´s New Ramps	10	32.65
3463	Robintron	6	22.22
3465	Drive through MegaCity	23	25.16
3466	Another Longest Common Subsequence Problem	6	42.86
3482	Alias	4	57.14