Sphere Online Judge (SPOJ)

list of classical problems

ID	NAME	QUALITY	USERS	ACC %	DIFFICULTY C I
13925	ZEROES IN RANGE V2	2	240	37.60	23 17
27484	Zeros in Fibonacci period	1	12	40.55
27519	Zeros of the fundamental Fibonacci period		8	34.31
14905	Zig when you zag	4	31	30.26	30 38
35295	zig-zag on the golden river	11	120	22.49	9 15
518	Zig-Zag Permutation	1	42	31.02	26 26
11946	Zig-Zag Permutation 2	1	5	39.29	26 34
7019	Zig-Zag rabbit	4	587	36.87	23 17
10623	ZNANSTVENIK	2	253	30.61	17 26
15439	Zombie Outbreak	5	69	25.74	21 21
9685	Zombie’s Treasure Chest	2	75	13.16	9 17
1554	Zoo		110	29.26
11384	Zoom Operation		4	20.00
4828	ZSequence		51	19.33
6340	ZUMA	6	461	44.40	17 34