Sphere Online Judge (SPOJ)

list of classical problems

ID	NAME	USERS	ACC %	DIFFICULTY C I
4459	Muzidabutur	31	25.33
4461	A Famous Airport Manager	23	16.36
4477	Flower growing	112	22.62
4478	Counting Expressions II	14	35.29
4523	Binomial Coefficients	207	41.27	23 12
4528	Frog Wrestling	66	43.23
4533	Determinant of Banded Matrices	16	32.67
4552	Adding up Triangles	137	36.30
4558	I Speak Whales	182	42.26	17 17
4559	A Day at the Races	122	17.08
4574	Riding in cycles	41	24.31
4586	Texas Trip	68	38.46
4588	SETI	127	67.19
4657	Gas Wars	139	35.32	34 17
4717	Grid Points in a Triangle	97	46.48
4785	Starship	10	28.80
4828	ZSequence	51	19.33
4881	Words on graphs	103	11.39	34
5011	Library for Madrid	55	42.17	17 17
5014	Crazy Receptionist	11	13.18
5015	Decode the Castanets	32	40.19
5016	Guernica	19	51.06
5018	Street Gambler	26	43.55
5102	Mystic Craft	55	45.51
5103	Top 10	40	15.79
5104	Spam Detection	14	20.69
5115	Two "Ways"	63	14.95
5143	Binary Integer	49	49.59
5144	Cryptography Reloaded (Act I)	33	26.16
5145	Déjà vu	16	19.23
5146	Experiment on a … Cable	12	41.38
5147	Fire-Control System	31	18.97	34 17
5149	History of Languages	27	15.54
5153	Compressed String	40	30.00
5154	Cryptography Reloaded (Act II)	31	27.89
5155	Exciting Time	41	13.42
5156	Flowers Placement	41	31.06
5158	Heroes Arrangement	12	12.80
5159	Island Explorer	34	15.28
5160	Jinyuetuan Puzzle	40	36.69
5163	Tower of Vientiane	92	40.20
5182	Double Sorting	12	8.88
5300	Mexican Standoff	21	23.19
5373	Four Mines	14	8.04
5446	Fishing Net	166	31.17
5462	Art Plagiarism	10	23.44
5522	Buy Your House	12	35.90
5523	Highway Patrol	15	47.95
5531	Kutevi Hard	88	43.17
5566	Math with Bases	15	11.28