Sphere Online Judge (SPOJ)

ID	NAME	QUALITY	USERS	DIFFICULTY C I
36941	AND Queries	4	21	23 34
3477	Baby	28	953	21 24
36653	Blind Escape II	3	12	23 28
2050	Strange Billboard	10	804	13 29
36946	March Of The King	3	16	45 45
151	The Courier	38	1069	22 23
40400	Count Set Bits		450	1 1
3877	Cvjetici	18	986	12 21
98	Dance Floor	3	727	12 12
35277	DNA of Elf	3	20	17 34
2530	Tiling a Grid With Dominoes	60	2437	16 24
10500	Haybale stacking	24	3999	9 14
2856	Help Bob	6	277	21 23
3436	Histogram	44	1542	19 22
12206	Hidden Password	10	845	11 6
18187	Ingredients	10	292	21 23
34063	Chiaki With Intervals (Easy)		22
5298	Interval Challenge	4	142	24 27
25179	Kaos	9	279	19 25
20957	Alia and 3 Khans	1	77	34 17
4329	Counting K-Rectangle	4	388	20 28
676	Sorting is not easy	9	541	19 32
3883	LATGACH3	55	3202	10 20
9386	Re-Arrange II	9	276	21 17
4480	Chaos Strings	14	533	17 22
3932	Point Connection Game in a Circle	3	767	13 21
3953	Paid Roads	8	261	19 26
18963	Bhagat The Bit Man	10	661	5 12
227	Ordering the Soldiers	22	1477	21 23
4180	Pizza Location	2	576	31 17
12734	Seating Arrangement	7	165	6 15
4201	Coder Ratings	26	1397	15 18
19216	Super Mario Revisited	6	22	20 23
27043	Subset Pattern		32	1 1
3749	Subset Sums	74	4210	17 20
15766	Enjoy Sum with Operations	15	375	20 26
10210	After Party Transfers	1	39	34 28
1700	Traveling by Stagecoach	9	476	17 16
15439	Zombie Outbreak	5	75	21 21
16487	Update the array !	165	5019	9 14
8916	Villages by the River	7	278	13 20
6294	Yodaness Level	74	3571	15 16

#bitmasks

Bitmask is data that is used for bitwise operations

https://en.wikipedia.org/wiki/Mask_(computing) https://en.wikipedia.org/wiki/Bitwise_operation https://en.wikipedia.org/wiki/Bitwise_operations_in_C https://en.wikipedia.org/wiki/Binary_number https://en.wikipedia.org/wiki/Subnetwork - applications of bitmasks in computer networks