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 ,, and fields. Then be sure to update the status on this page to indicate that we have a solution!

1 The problems

These problems have been split into 11 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 94: Miscellaneous problems
• Questions 95 to 99: Miscellaneous problems, continued

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

2 Solutions

Known solutions are listed at 99 questions/Solutions. We still lack Haskell solutions to problems 80,82,83,85,86 and 94. Please update this page if you find solutions to these. Some of those we have could do with cleaning up or additional solutions.

3 References

• P-99: Ninety-Nine Prolog Problems contains Prolog solutions to all the problems.
• L-99: Ninety-Nine Lisp Problems contains Lisp solutions to problems 1-11, 14, 15, 17 and 20-28.
• 99 Problems in Perl 6 has an increasing number of Perl 6 solutions (running on Pugs).
• 99 Problems in OCaml contains Ocaml solutions to many problems.

A gentle introduction to haskell

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Paul Hudak, Yale University
John Peterson, Yale University
Joseph Fasel, Los Alamos National Laboratory

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June 2000

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This is the master HTML version of the Gentle Introduction To Haskell, version 98. Revised June, 2000 by Reuben Thomas. You may download the following:

• Postscript (.ps.gz, 221K)
• gzipped PDF (.pdf.gz, 273K)
• PDF (.pdf, 434K)
• DVI (.tar.gz, 127K)
• HTML (.tar.gz, 113K), code files included.
• Haskell source code (.tar.gz, 27K)
• Document sources (.tar.gz, 151K)

Brief Table of Contents.

• Introduction
• Values, Types, and Other Goodies
• Functions
• Case Expressions and Pattern Matching
• Type Classes and Overloading
• Types, Again
• Input/Output
• Standard Haskell Classes
• Monads
• Numbers
• Modules
• Typing Pitfalls
• Arrays
• The Next Stage
• Bibliography
• Complete Table of Contents

All code in this tutorial, with additional commentary, is found in the code directory packaged with this tutorial. We suggest that you inspect, run, and modify this code as you read the tutorial. This code has been tested on Hugs 98.
Premission is granted to correct, improve, or enhance this document. If you wish to publish updated versions of the tutorial on haskell.org please contact John Peterson.
Copyright (C) 1999 Paul Hudak, John Peterson and Joseph Fasel
Permission is hereby granted, free of charge, to any person obtaining a copy of "A Gentle Introduction to Haskell" (the Text), to deal in the Text without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Text, and to permit persons to whom the Text is furnished to do so, subject to the following condition: The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Text.