H-99: Ninety-Nine Haskell Problems

These are Haskell translations of Ninety-Nine Lisp Problems, which are themselves translations of Ninety-Nine Prolog Problems.

If you want to work on one of these, put your name in the block so we know someone's working on it. Then, change n in your block to the appropriate problem number, and fill in the <Problem description>,<example in lisp>,<example in Haskell>,<solution in haskell> and <description of implementation> fields. Then be sure to update the scoreboard on this page to indicate that we have a solution!

The problems

These problems have been split into 10 parts, for ease of access.

• Questions 1 to 10: Lists
• Questions 11 to 20: Lists, continued
• Questions 21 to 28: Lists again
• Questions 31 to 41: Arithmetic
• Questions 46 to 50: Logic and codes
• Questions 54A to 60: Binary trees
• Questions 61 to 69: Binary trees, continued
• Questions 70B to 73: Multiway trees
• Questions 80 to 89: Graphs
• Questions 90 to 99: Miscellaneous problems

(Though the problems number from 1 to 99, there are some gaps and some additions marked with letters. There are actually only 88 problems.)

Scoreboard

Scoreboard

Problem	Lisp solution?	Haskell Solution?
1	Yes	Yes
2	Yes	Yes
3	Yes	Yes
4	Yes	Yes
5	Yes	Yes
6	Yes	Yes
7	Yes	Yes
8	Yes	Yes
9	Yes	Yes
10	Yes	Yes
11	Yes	Yes
12	No	Yes
13	No	Yes
14	Yes	Yes
15	Yes	Yes
16	No	Yes
17	Yes	Yes
18	No	Yes
19	No	Yes
20	Yes	Yes
21	Yes	Yes
22	Yes	Yes
23	Yes	Yes
24	Yes	Yes
25	Yes	Yes
26	Yes	Yes
27	Yes	Yes
28	Yes	Yes
31	No	Yes
32	No	Yes
33	No	Yes
34	No	Yes
35	No	Yes
36	No	Yes
37	No	Yes
38	n/a	n/a
39	No	Yes
40	No	Yes
41	No	Yes
46	No	Yes
47	No	Yes
48	No	Yes
49	No	Yes
50	No	Yes
54A	No	n/a
55	No	Yes
56	No	Yes
57	No	Yes
58	No	Yes
59	No	No
60	No	No
61	No	Yes
61A	No	Yes
62	No	Yes
62B	No	Yes
63	No	No
64	No	Yes
65	No	Yes
66	No	Yes
67	No	No
68	No	No
69	No	No
70B	No	n/a
70C	No	Yes
70	No	Yes
71	No	Yes
72	No	Yes
73	No	Yes
80	No	No
81	No	No
82	No	No
83	No	No
84	No	No
85	No	No
86	No	No
87	No	No
88	No	No
89	No	No
90	No	Yes
91	No	Yes
92	No	No
93	No	Yes
94	No	No
95	No	Yes
96	No	Yes
97	No	Yes
98	No	No
99	No	No