Sphere Online Judge (SPOJ)

list of classical problems

ID	NAME	USERS	ACC %	DIFFICULTY C I
3641	Earthquakes	23	37.68
3642	Pretty Printing	39	24.38
3645	Farthest Headquarters	55	25.80
3646	Adventure Tourism	44	17.28
3647	Moebius	1	2.67
3678	Cattle Bruisers	86	25.65
3733	Trezor	98	52.10
3762	Bread Tree	161	13.50
3867	Who is The Boss	162	24.56
3872	Party At School	49	24.38
3884	When (You Believe)	23	8.98
3890	Rectangles Counting	173	33.28
3893	Space settlement	64	43.31
3894	Bouncing Balls	27	37.74
3895	Matrix Game	25	31.71
3900	MinCut Query	77	28.78
3901	Black and White Nim	55	44.50
3922	Mystical River	127	25.47
3926	Manhattan Wire	81	14.32
3927	Polygon on the Grid	22	36.62
3929	Different Digits	71	22.60
3930	Group Partition	67	29.94
3935	SHIFT Operator on Matrix	187	42.04
3939	Search of Concatenated Strings	27	26.32
3941	Kth Shortest Path	26	29.38
3942	Cleaning Robot	30	66.15
3961	Journey with Pigs	129	43.57
3965	Minimax Triangulation	58	34.60
3970	Convert to Decimal Base System	53	40.29	17 17
3972	Stargates	45	13.29
3981	Shortest Regular Bracket	80	35.85
4003	Subway planning	40	18.08
4004	Exploding CPU	141	46.17
4008	Con Voi	7	62.50
4010	Chặt cây	7	42.86
4021	Bipalindrome	182	30.80
4034	Pizza Delivery	53	17.10
4052	Game	75	33.70
4060	A game with probability	189	21.14
4062	Rob Mini-Safe	111	39.21
4069	Morphing is Fun	31	23.08
4070	Two Professors	101	14.47
4083	Tele Broadcast	62	49.46
4097	Locomotive	34	44.30
4142	Ellipse	17	8.46
4154	IZBORI	36	24.54
4156	PLAHTE	64	35.75
4160	A1 Road	86	50.46
4178	Distance on a square lattice	122	54.32
4185	Cube	52	35.93