Sphere Online Judge (SPOJ)

list of classical problems

ID	NAME	QUALITY	USERS	ACC %	DIFFICULTY C I
241	Arranging the Blocks		54	12.78
261	Triangle Partitioning		205	58.33
275	The Water Ringroad		7	19.15
292	Alibaba	1	187	23.39
293	Officers on the Beat		11	16.23
296	Teamwork is Crucial		71	29.97
325	The Tall Windmills		82	22.57	34
350	Landscaping	1	99	30.08
363	Crane Operator		5	2.71
380	Bullshit Bingo		722	33.74
383	European railroad tracks		227	30.31
386	Help the problem setter		105	45.45
404	Scanner		59	12.57
418	Necklace		47	17.18
698	Plane Hopping	1	289	25.31	17
760	Convex Hull 3D		126	41.31
850	Soccer Choreography		4	3.80
866	DNA Translation		117	21.44
999	Generalized Matrioshkas		420	32.59
1270	Paint By Numbers		28	23.24
1483	Colorful Lights Party		13	10.20
1536	Help Blue Mary Please! (Act III)		30	14.42
1554	Zoo		115	28.60
1695	Grandpa’s Rubik Cube	1	111	60.94
1701	Earth Observation with a Mobile Robot Team		14	40.54
1708	Square Count		75	30.98
1709	Swamp Things		290	40.40
1722	Life, the Universe, and Everything II		68	28.49
1731	Counting Triangles III	1	266	33.78
1739	Yet Another Equation		237	41.51
1815	Problems Collection (Volume X)		77	7.26
1842	Lineland Airport		37	18.84
1877	Enrich my purse		153	27.01
1880	Hanoi Calls		205	54.44
1962	Circles		62	20.12
1963	Image Projections		109	34.26
1964	Tree cut		149	38.10
1966	Ski Valley		117	18.43
2002	Random Number Generator		98	40.62
2019	The Rolling Ball		4	5.48
2022	Truth Or Lie		104	21.17
2031	Please help You-Know-Who		39	28.65
2047	Stone Removing Game	-1	133	37.96
2052	Hexagonal Parcels		76	28.93
2060	Tough Water Level		36	18.21
2129	Cake		70	21.59
2130	Trolls		29	39.19
2132	Puzzle		89	32.68
2140	(un)Fair Play		75	38.08
2141	Golden Garden		17	12.20