Sphere Online Judge (SPOJ)

list of classical problems

ID	NAME	QUALITY	USERS	ACC %	DIFFICULTY C I
3415	Shrinking Polygons		235	19.45
3420	Falling Ice		7	14.58
3461	Song Contest		15	14.95
3462	The Skatepark´s New Ramps		9	10.75
3463	Robintron		7	20.90
3465	Drive through MegaCity		23	20.54
3466	Another Longest Common Subsequence Problem		6	5.71
3482	Alias		6	28.57
3483	Begin		4	8.13
3485	Disputes	1	86	63.75
3486	Elimination		74	30.09
3490	Hidden Triangle		10	26.67
3495	The Nobel Thief		13	50.00
3533	Game on board		26	31.14
3543	Matrica		55	39.59
3582	Restaurant Tab		24	22.33
3640	Hanoi Subway System Construction		34	39.60
3641	Earthquakes		25	35.37
3642	Pretty Printing		39	21.71
3645	Farthest Headquarters		60	26.80
3646	Adventure Tourism		46	14.43
3647	Moebius		2	2.36
3678	Cattle Bruisers		89	26.07
3679	Moo University - Emergency Pizza Order	-1	36	27.05
3725	Taming a T-REX	1	150	44.20	34
3733	Trezor		104	52.19
3762	Bread Tree		163	13.62
3867	Who is The Boss		169	25.29
3872	Party At School		56	24.62
3876	Tablica	1	206	58.65
3884	When (You Believe)		23	8.66
3890	Rectangles Counting		175	33.61
3893	Space settlement		67	32.13
3894	Bouncing Balls		28	31.54
3895	Matrix Game		26	22.69
3898	Even Palindrome	-1	250	10.22
3900	MinCut Query		78	29.06
3901	Black and White Nim		55	39.23
3922	Mystical River		126	25.38
3926	Manhattan Wire		80	14.07
3927	Polygon on the Grid		23	30.34
3929	Different Digits		73	22.56
3935	SHIFT Operator on Matrix		189	42.12
3939	Search of Concatenated Strings		28	25.79
3941	Kth Shortest Path		25	24.70
3942	Cleaning Robot		33	64.00
3961	Journey with Pigs		133	42.15
3965	Minimax Triangulation		58	34.43
3972	Stargates		47	13.58
3981	Shortest Regular Bracket		81	33.45