Sphere Online Judge (SPOJ)

list of classical problems

ID	NAME	QUALITY	USERS	ACC %	DIFFICULTY C I
6693	C - Karaoke		5	20.00
9694	Quelling Blade		5	33.33
11946	Zig-Zag Permutation 2	1	5	39.29	26 34
12804	Spy		5	21.15
13365	Move the boulder		5	10.34
15088	Ancient Aliens		5	52.00	34 1
15092	A Kleene Implementation		5	44.44
25450	When Does The World End	1	5	5.69	34 50
26181	Walking Jumper		5	28.57
27494	Happiness		5	18.64
32578	Meh and Mini Splendor		5	60.00
34315	The Chase		5	14.81
35810	Prismata	1	5	7.69	34 17
36534	Heroes		5	22.73
41890	Anagrams and Divisibility		5	5.98
850	Soccer Choreography		4	4.02
2419	G-Line Grid	1	4	7.14
3482	Alias		4	57.14
3483	Begin		4	11.11
4189	Landing		4	3.64
11384	Zoom Operation		4	20.00
11900	Spelling Suggestion		4	12.82
12806	Blackjack		4	27.78
12855	Teleport		4	14.63	17 34
13882	THE WITTY BOY	1	4	4.31	34 17
13926	Flipping Slipping of grids	1	4	25.00	17 50
13945	GHALIBS CHALLENGE		4	33.33
15382	Factorial (Again!)		4	41.38	50 1
17779	Charlie and the Chocolate Factory		4	11.90
21969	Money Transfers		4	23.81
22675	A conjecture of Paul Erdős (hard)	2	4	5.56	34 34
25336	Eefun Plays Doto		4	31.03
26183	Laser Beam 2.0	1	4	18.18	17 17
26843	Who is the Best?		4	28.57
34357	Ludic Numbers (hard)	2	4	17.91
34379	Another Travelling Salesman Problem	1	4	33.33	34
34973	Yet Another Subset Sum Problem	2	4	3.51	26 34
2019	The Rolling Ball		3	5.26
6957	Partial Palindrome		3	8.33
12805	Age of Empires		3	15.62
13816	Pheversos Game		3	23.53
14665	Delta catheti (hard)	1	3	17.50
14700	Delta catheti II (Hard)	1	3	7.55
15091	One Good Base Deserves Another		3	57.14	34 1
15381	Cut The Rope		3	17.95	42 1
22177	RajaRani	3	3	4.35	17 17
32028	Ada and Parties		3	1.27	50 50
34385	Pripyat		3	15.00
41790	Spy Reloaded		3	8.51
275	The Water Ringroad		2	9.30