Sphere Online Judge (SPOJ)

list of challenge problems

ID	NAME	QUALITY	USERS	ACC %	DIFFICULTY C I
3880	Nop	1	607	49.87	1 1
4163	Relative Board		6	38.10
4246	Place the Numbers II	1	540	66.32	1 1
5842	Polybius square	2	1026	59.23	34 12
6125	Dos Date	2	788	55.80	17 6
6173	Burned Pancakes Tower	1	23	64.61	17 17
6295	Area Difference	2	388	44.61	6 5
6646	Fully Parenthesized Expression		26	43.75
7063	Cycles, More Cycles		16	83.43
7225	Word To Number	2	156	61.22	17 9
7480	Nth Prime	4	618	45.56	26 12
8638	Sum of Fibonacci numbers	1	135	72.81	50 34
8675	Equation Check	1	262	57.52	1 9
8950	Grid points		44	57.73
11410	Find New SPOJ Problems		8	42.96
12845	Minimum knight moves Challenge	3	343	72.13	34 17
13366	TWO KINGS		17	62.42
26321	God Number is 20 (Rubik)	1	25	65.86	34 1
27840	Seedlings		34	74.92
27841	Sabotage	2	30	56.37	34 34