Sphere Online Judge (SPOJ)

list of classical problems

ID	NAME	USERS	ACC %	DIFFICULTY C I
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	52.22
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	22.93
8429	Array Sorting	62	16.26
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
8951	brownie	62	48.75
8971	LQDNUMBERS	31	36.44
8992	A los saltos	36	30.82
9000	Bob and his new kite factory	2	1.42
9030	Bob and his towers	38	31.76
9038	Chessboard Billiard	45	24.91
9063	Shuffling cards	17	31.65
9084	Journey to Mars	89	23.20
9086	Formula 3D	6	21.21
9118	Genetic Fraud	149	29.67
9121	Magical Crafting	56	47.48
9123	Security Zone	36	27.22
9124	Sightseeing	116	17.61
9125	Suiting Weavers	84	29.38
9137	Pyramid Sums	92	34.78	34 17
9161	Legendre symbol	184	45.30	9 9
9190	Perfect Maze	31	1.73