Sphere Online Judge (SPOJ)

list of classical problems

ID	NAME	USERS	ACC %	DIFFICULTY C I
8055	Playground	276	25.75
8062	Shopping Rush	71	63.59
8074	God of Number Theory	25	41.98
8097	Islands	69	46.30
8099	Crash´s number table	93	20.08
8104	Friendly Knights	147	45.38
8108	POLYU	32	27.65
8189	Circles On A Screen	81	28.40
8265	Zero Count	14	13.89
8282	Distance	51	25.88
8286	Perfect Matching	90	18.98	1 17
8316	Win gold medal	55	27.37
8317	Red Balls	43	44.84
8318	color the balls	66	45.93	50 50
8320	Spreadsheet scrolling	75	32.63
8321	Chocolate distribution	115	24.51
8323	Triangle equality	58	43.85
8325	Partitioning the plane	37	39.49
8326	Leaky containers	31	41.84
8327	Progressive progressions	53	66.10
8328	Move the books	27	33.33
8331	Sister cities	36	52.75
8332	Ski slopes	24	21.90
8333	Place-name game	69	37.88
8421	Fun With Inequalities	140	38.05	17 17
8423	Recover Polynomials	51	48.25
8427	Permutation Game	32	41.05
8428	Grid Tiling	23	23.08
8429	Array Sorting	64	17.04
8433	Revenge of the squares (variation)	484	49.00	17 17
8461	Adventure in Moving	43	27.98
8478	Ancient Pocket Calculator	7	4.44
8542	Modern Pocket Calculator	35	9.15	28 6
8546	Manoj and Pankaj	51	23.05
8593	Covering the Corral	8	31.58
8594	Tails all the way	287	34.27
8627	I2C	32	25.79
8628	Selling Land	70	46.89
8657	The Bovine Accordion and Banjo Orchestra	6	25.00
8661	Bogosort	42	14.33
8663	Squares Game	34	48.75
8666	Maximum - Profit -- Version II	91	43.61	1 1
8816	Mravograd	29	32.00	17 34
8836	Yet Another Sequence Problem	73	23.62
8844	Detection of Extraterrestrial	118	36.36
8846	Fudan Extracurricular Lives	7	25.00
8848	Herbicide	18	41.56
8849	Imitation	23	38.36
8886	Guess number!	17	5.03	34 34
8945	Grid points (speed variation)	24	24.68