Sphere Online Judge (SPOJ)

list of classical problems

ID	NAME	QUALITY	USERS	ACC %	DIFFICULTY C I
4528	Frog Wrestling		68	37.26
4533	Determinant of Banded Matrices		20	33.33
4551	Match Maker	1	61	22.28
4552	Adding up Triangles		140	35.10
4559	A Day at the Races		125	17.31
4574	Riding in cycles		43	23.95
4585	Star Wars	1	76	35.45
4586	Texas Trip		69	38.57
4588	SETI		129	66.41
4717	Grid Points in a Triangle		98	46.49
4785	Starship		13	29.77
4828	ZSequence		53	18.80
4881	Words on graphs		107	11.88	34
5014	Crazy Receptionist		11	12.06
5015	Decode the Castanets		35	40.17
5016	Guernica		25	60.78
5018	Street Gambler		30	47.06
5093	Pretty Functions	1	41	22.19
5102	Mystic Craft		57	46.20
5103	Top 10		42	15.81
5104	Spam Detection		16	15.97
5115	Two "Ways"		65	15.47
5143	Binary Integer		53	50.00
5144	Cryptography Reloaded (Act I)		34	26.43
5145	Déjà vu		17	15.12
5146	Experiment on a … Cable		15	34.88
5149	History of Languages		31	17.11
5150	Junk-Mail Filter		133	21.53
5153	Compressed String		44	27.46
5154	Cryptography Reloaded (Act II)		35	27.14
5155	Exciting Time		44	13.90
5156	Flowers Placement		43	31.74
5158	Heroes Arrangement		16	12.43
5159	Island Explorer		37	15.77
5160	Jinyuetuan Puzzle		44	37.36
5163	Tower of Vientiane		104	34.79
5182	Double Sorting		15	8.70
5197	Differential Diagnosis	1	64	24.12
5296	Air Combat	-1	68	15.20	34
5300	Mexican Standoff		25	23.78
5373	Four Mines		14	6.32
5446	Fishing Net		172	31.73
5462	Art Plagiarism		11	23.19
5522	Buy Your House		16	38.46
5523	Highway Patrol		18	41.76
5531	Kutevi Hard		90	43.40
5566	Math with Bases		15	11.06
5637	LL and ErBao		5	41.43
5672	Captain Selection	-1	10	28.57
5831	Permutation Jumping		136	59.33