Sphere Online Judge (SPOJ)

ID	NAME	QUALITY	USERS	DIFFICULTY C I
30785	Ada and Apple	12	192	29 23
32952	Ada and Football	3	214	45 39
32223	Ada and Lychees	3	14	42 26
28449	Ada and List	11	312	14 17
32856	Ada and Contact	2	25	34 34
30760	Ada and Travelling Salesman	18	182	23 29
15454	How to Handle the Fans	39	1518	12 11
5832	AND Rounds	51	1694	17 20
27379	Unique Code	21	125	20 20
61	Brackets	175	5455	19 20
14742	Building Bridges(HARD)	10	449	14 17
6168	Building Bridges	27	1646	11 17
23742	Dolan and Nephews	6	48	31 28
33019	Catering Contracts	7	87	23 27
12563	Halt The War	8	392	19 19
13015	Counting Primes	33	1398	16 14
7296	Trees Again	5	166	21 30
9722	Insertion Sort	28	3896	12 12
5296	Air Combat	-1	64	34
10628	Count on a tree	63	2452	32 31
10707	Count on a tree II	67	3132	31 30
11414	Combat on a tree	2	239	30 34
11482	Count on a trie		60	42 50
16245	Living with Courage	20	569	10 13
1108	Card Trick	68	2197	21 24
10810	Its a Murder!	55	2386	16 17
3978	Distance Query	70	1769	24 21
3267	D-query	454	13054	19 23
9577	Dynamic Tree Connectivity	12	581	29 28
1684	Frequent values	111	3856	20 21
18185	Give Away	33	1137	20 19
11985	Gao on a tree	26	798	28 27
12005	Grass Planting	11	547	29 19
1043	Can you answer these queries I	567	13794	25 24
1557	Can you answer these queries II	24	1619	29 35
1716	Can you answer these queries III	234	11359	22 21
2713	Can you answer these queries IV	60	4007	21 21
2916	Can you answer these queries V	51	2691	23 23
4487	Can you answer these queries VI	26	1287	34 28
6779	Can you answer these queries VII	17	1288	38 27
19543	Can you answer these queries VIII	8	200	37 35
132	Help R2-D2!	12	762	19 16
12210	High and Low		61
8002	Horrible Queries	397	10895	19 18
18247	Arrangement Validity	11	213	17 21
18248	Maggu’s Solar Panels	1	42	34 34
26721	I LOVE Kd-TREES III	4	80	34 34
37375	Kingdom of Equality	2	11	26 26
3693	Maximum Sum	58	6482	19 18
8985	Line up	19	400	16 17

#tree

Tree is a data structure that simulates a hierarchical tree structure

https://en.wikipedia.org/wiki/Tree_(data_structure) https://en.wikibooks.org/wiki/Data_Structures/Trees http://www.i-programmer.info/babbages-bag/477-trees.html