Sphere Online Judge (SPOJ)

list of classical problems (unsolved)

ID	NAME	QUALITY	USERS	ACC %	DIFFICULTY C I
5373	Four Mines		14	6.25
5446	Fishing Net		176	31.96
5462	Art Plagiarism		13	21.84
5522	Buy Your House		17	39.62
5523	Highway Patrol		19	43.01
5531	Kutevi Hard		90	43.40
5566	Math with Bases		15	10.78
5637	LL and ErBao		5	41.43
5672	Captain Selection	-1	10	26.42
5831	Permutation Jumping		137	59.48
5973	Selecting Teams		235	23.33
6052	PBCGAME		85	27.45
6059	Another GCD problem		342	45.16
6230	Dictionary order		6	9.30
6292	Shmoogle Wave		17	23.01
6296	Experiment		34	23.08
6500	Counting Diameter		38	28.21
6503	Travelling Salesman Again !		92	35.17
6652	Skiers		35	47.26
6690	A - Comparison Expressions		57	33.22
6693	C - Karaoke		26	56.18
6695	E - Publish of Perish	1	714	39.98
6706	Making Chess Boards		27	22.88
6709	Multiplying by Rotation	1	92	51.94
6711	Transform a Sequence		41	30.94
6720	Paper Fold		19	12.21
6732	Camels		88	37.93
6738	Nice Quadrangles		180	40.97
6767	Sequence Function		14	18.52
6804	Cheating or Not		19	15.29
6819	Yet Another Assignment Problem	1	42	11.26	1
6823	Seller Bob		73	21.72
6827	Last Minute Construction		24	17.36
6831	Two Ball Game		67	28.44
6832	To Score or not to score		46	29.01
6851	Fence		43	24.40
6860	Asistent		25	13.45
6885	Wonkas Oompa-Impa Dilemma		16	22.22
6895	Maximum Edge of Powers of Permutation		12	21.39
6951	MP3 Player		42	28.57
6957	Partial Palindrome		3	5.00
6977	Odd Independent Sets		17	51.28
6981	The Least Number		23	24.43
6985	Rearranging Digits		56	22.53
6986	Summing Slopes		61	28.79
6999	Avoiding SOS Grids		69	10.71
7010	Police Business		6	25.00
7023	Cookies		19	28.80
7050	Necklace Decomposition		48	60.61
7100	Back To The Polygon		88	34.80