Sphere Online Judge (SPOJ)

list of challenge problems

ID	NAME	QUALITY	USERS	ACC %	DIFFICULTY C I
270	Digits of Pi	13	5869	71.28	9 19
314	Digits of e	5	2996	59.54	3 3
525	Fractions Calculator		53	41.53
1416	Electrification		35	38.19
1558	Math II		36	73.24
2624	JawBreaker Game	1	86	61.16	26 26
4246	Place the Numbers II	1	540	66.32	1 1
5842	Polybius square	2	1025	59.25	34 12
6125	Dos Date	2	788	55.81	17 6
6295	Area Difference	2	388	44.61	6 5
7105	Reverse the Input	3	544	34.53	28 12
8638	Sum of Fibonacci numbers	1	135	72.81	50 34
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