Sphere Online Judge (SPOJ)

list of classical problems

ID	NAME	QUALITY	USERS	ACC %	DIFFICULTY C I
3254	Guard		14	51.72
3305	Roman Patrollers		45	59.26
3307	Hex Tile Equations	1	35	42.45
3309	Bulletin Board		19	20.80
3347	Cestarine		59	34.58
3359	Stack		45	15.60
3360	Digital Image Recognition		25	8.19
3372	Round Table	1	57	45.00
3373	Permutation Code		41	55.70
3393	Knot or Not		6	13.56
3406	Bases		68	21.12
3412	Higgs Boson		48	18.93
3415	Shrinking Polygons		230	18.87
3420	Falling Ice		7	24.14
3461	Song Contest		12	14.44
3462	The Skatepark´s New Ramps		10	32.65
3463	Robintron		6	22.22
3465	Drive through MegaCity		23	25.16
3466	Another Longest Common Subsequence Problem		6	42.86
3482	Alias		4	57.14
3483	Begin		4	11.11
3485	Disputes		80	62.59
3486	Elimination		67	28.57
3490	Hidden Triangle		9	28.85
3492	Braille Transcription	-1	10	12.32
3495	The Nobel Thief		6	38.10
3533	Game on board		28	36.73
3543	Matrica		53	39.38
3582	Restaurant Tab		24	27.27
3640	Hanoi Subway System Construction		32	41.75
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	2.60
3678	Cattle Bruisers		86	25.65
3679	Moo University - Emergency Pizza Order	-1	35	26.42
3725	Taming a T-REX	1	145	44.58	34
3733	Trezor		99	52.26
3762	Bread Tree		161	13.50
3867	Who is The Boss		162	24.56
3872	Party At School		49	24.38
3876	Tablica	1	205	59.13
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
3898	Even Palindrome	-1	247	10.24
3900	MinCut Query		77	28.78