Difference between revisions of "H-99: Ninety-Nine Haskell Problems"

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We simply group equal values together (group), then take the head of each.
 
We simply group equal values together (group), then take the head of each.
  +
  +
== Problem 9 ==
  +
  +
<Problem description>
  +
  +
<pre>
  +
Example:
  +
<example in lisp>
  +
  +
Example in Haskell:
  +
<example in Haskell>
  +
</pre>
  +
  +
Solution:
  +
<haskell>
  +
<solution in haskell>
  +
</haskell>
  +
  +
<description of implementation>
  +
  +
== Problem 10 ==
  +
  +
<Problem description>
  +
  +
<pre>
  +
Example:
  +
<example in lisp>
  +
  +
Example in Haskell:
  +
<example in Haskell>
  +
</pre>
  +
  +
Solution:
  +
<haskell>
  +
<solution in haskell>
  +
</haskell>
  +
  +
<description of implementation>
  +
  +
== Problem 11 ==
  +
  +
<Problem description>
  +
  +
<pre>
  +
Example:
  +
<example in lisp>
  +
  +
Example in Haskell:
  +
<example in Haskell>
  +
</pre>
  +
  +
Solution:
  +
<haskell>
  +
<solution in haskell>
  +
</haskell>
  +
  +
<description of implementation>
  +
  +
== Problem 12 ==
  +
  +
<Problem description>
  +
  +
<pre>
  +
Example:
  +
<example in lisp>
  +
  +
Example in Haskell:
  +
<example in Haskell>
  +
</pre>
  +
  +
Solution:
  +
<haskell>
  +
<solution in haskell>
  +
</haskell>
  +
  +
<description of implementation>
  +
  +
== Problem 13 ==
  +
  +
<Problem description>
  +
  +
<pre>
  +
Example:
  +
<example in lisp>
  +
  +
Example in Haskell:
  +
<example in Haskell>
  +
</pre>
  +
  +
Solution:
  +
<haskell>
  +
<solution in haskell>
  +
</haskell>
  +
  +
<description of implementation>
  +
  +
== Problem 14 ==
  +
  +
<Problem description>
  +
  +
<pre>
  +
Example:
  +
<example in lisp>
  +
  +
Example in Haskell:
  +
<example in Haskell>
  +
</pre>
  +
  +
Solution:
  +
<haskell>
  +
<solution in haskell>
  +
</haskell>
  +
  +
<description of implementation>
  +
  +
== Problem 15 ==
  +
  +
<Problem description>
  +
  +
<pre>
  +
Example:
  +
<example in lisp>
  +
  +
Example in Haskell:
  +
<example in Haskell>
  +
</pre>
  +
  +
Solution:
  +
<haskell>
  +
<solution in haskell>
  +
</haskell>
  +
  +
<description of implementation>
  +
  +
== Problem 16 ==
  +
  +
<Problem description>
  +
  +
<pre>
  +
Example:
  +
<example in lisp>
  +
  +
Example in Haskell:
  +
<example in Haskell>
  +
</pre>
  +
  +
Solution:
  +
<haskell>
  +
<solution in haskell>
  +
</haskell>
  +
  +
<description of implementation>
  +
  +
== Problem 17 ==
  +
  +
<Problem description>
  +
  +
<pre>
  +
Example:
  +
<example in lisp>
  +
  +
Example in Haskell:
  +
<example in Haskell>
  +
</pre>
  +
  +
Solution:
  +
<haskell>
  +
<solution in haskell>
  +
</haskell>
  +
  +
<description of implementation>
  +
  +
== Problem 18 ==
  +
  +
<Problem description>
  +
  +
<pre>
  +
Example:
  +
<example in lisp>
  +
  +
Example in Haskell:
  +
<example in Haskell>
  +
</pre>
  +
  +
Solution:
  +
<haskell>
  +
<solution in haskell>
  +
</haskell>
  +
  +
<description of implementation>
  +
  +
== Problem 19 ==
  +
  +
<Problem description>
  +
  +
<pre>
  +
Example:
  +
<example in lisp>
  +
  +
Example in Haskell:
  +
<example in Haskell>
  +
</pre>
  +
  +
Solution:
  +
<haskell>
  +
<solution in haskell>
  +
</haskell>
  +
  +
<description of implementation>
  +
  +
== Problem 20 ==
  +
  +
<Problem description>
  +
  +
<pre>
  +
Example:
  +
<example in lisp>
  +
  +
Example in Haskell:
  +
<example in Haskell>
  +
</pre>
  +
  +
Solution:
  +
<haskell>
  +
<solution in haskell>
  +
</haskell>
  +
  +
<description of implementation>
  +
  +
== Problem 21 ==
  +
  +
<Problem description>
  +
  +
<pre>
  +
Example:
  +
<example in lisp>
  +
  +
Example in Haskell:
  +
<example in Haskell>
  +
</pre>
  +
  +
Solution:
  +
<haskell>
  +
<solution in haskell>
  +
</haskell>
  +
  +
<description of implementation>
  +
  +
== Problem 22 ==
  +
  +
<Problem description>
  +
  +
<pre>
  +
Example:
  +
<example in lisp>
  +
  +
Example in Haskell:
  +
<example in Haskell>
  +
</pre>
  +
  +
Solution:
  +
<haskell>
  +
<solution in haskell>
  +
</haskell>
  +
  +
<description of implementation>
  +
  +
== Problem 23 ==
  +
  +
<Problem description>
  +
  +
<pre>
  +
Example:
  +
<example in lisp>
  +
  +
Example in Haskell:
  +
<example in Haskell>
  +
</pre>
  +
  +
Solution:
  +
<haskell>
  +
<solution in haskell>
  +
</haskell>
  +
  +
<description of implementation>
  +
  +
== Problem 24 ==
  +
  +
<Problem description>
  +
  +
<pre>
  +
Example:
  +
<example in lisp>
  +
  +
Example in Haskell:
  +
<example in Haskell>
  +
</pre>
  +
  +
Solution:
  +
<haskell>
  +
<solution in haskell>
  +
</haskell>
  +
  +
<description of implementation>
  +
  +
== Problem 25 ==
  +
  +
<Problem description>
  +
  +
<pre>
  +
Example:
  +
<example in lisp>
  +
  +
Example in Haskell:
  +
<example in Haskell>
  +
</pre>
  +
  +
Solution:
  +
<haskell>
  +
<solution in haskell>
  +
</haskell>
  +
  +
<description of implementation>
  +
  +
== Problem 26 ==
  +
  +
<Problem description>
  +
  +
<pre>
  +
Example:
  +
<example in lisp>
  +
  +
Example in Haskell:
  +
<example in Haskell>
  +
</pre>
  +
  +
Solution:
  +
<haskell>
  +
<solution in haskell>
  +
</haskell>
  +
  +
<description of implementation>
  +
  +
== Problem 27 ==
  +
  +
<Problem description>
  +
  +
<pre>
  +
Example:
  +
<example in lisp>
  +
  +
Example in Haskell:
  +
<example in Haskell>
  +
</pre>
  +
  +
Solution:
  +
<haskell>
  +
<solution in haskell>
  +
</haskell>
  +
  +
<description of implementation>
  +
  +
== Problem 28 ==
  +
  +
<Problem description>
  +
  +
<pre>
  +
Example:
  +
<example in lisp>
  +
  +
Example in Haskell:
  +
<example in Haskell>
  +
</pre>
  +
  +
Solution:
  +
<haskell>
  +
<solution in haskell>
  +
</haskell>
  +
  +
<description of implementation>
  +
  +
== Problem 29 ==
  +
  +
<Problem description>
  +
  +
<pre>
  +
Example:
  +
<example in lisp>
  +
  +
Example in Haskell:
  +
<example in Haskell>
  +
</pre>
  +
  +
Solution:
  +
<haskell>
  +
<solution in haskell>
  +
</haskell>
  +
  +
<description of implementation>
  +
  +
== Problem 30 ==
  +
  +
<Problem description>
  +
  +
<pre>
  +
Example:
  +
<example in lisp>
  +
  +
Example in Haskell:
  +
<example in Haskell>
  +
</pre>
  +
  +
Solution:
  +
<haskell>
  +
<solution in haskell>
  +
</haskell>
  +
  +
<description of implementation>
  +
  +
== Problem 31 ==
  +
  +
<Problem description>
  +
  +
<pre>
  +
Example:
  +
<example in lisp>
  +
  +
Example in Haskell:
  +
<example in Haskell>
  +
</pre>
  +
  +
Solution:
  +
<haskell>
  +
<solution in haskell>
  +
</haskell>
  +
  +
<description of implementation>
  +
  +
== Problem 32 ==
  +
  +
<Problem description>
  +
  +
<pre>
  +
Example:
  +
<example in lisp>
  +
  +
Example in Haskell:
  +
<example in Haskell>
  +
</pre>
  +
  +
Solution:
  +
<haskell>
  +
<solution in haskell>
  +
</haskell>
  +
  +
<description of implementation>
  +
  +
== Problem 33 ==
  +
  +
<Problem description>
  +
  +
<pre>
  +
Example:
  +
<example in lisp>
  +
  +
Example in Haskell:
  +
<example in Haskell>
  +
</pre>
  +
  +
Solution:
  +
<haskell>
  +
<solution in haskell>
  +
</haskell>
  +
  +
<description of implementation>
  +
  +
== Problem 34 ==
  +
  +
<Problem description>
  +
  +
<pre>
  +
Example:
  +
<example in lisp>
  +
  +
Example in Haskell:
  +
<example in Haskell>
  +
</pre>
  +
  +
Solution:
  +
<haskell>
  +
<solution in haskell>
  +
</haskell>
  +
  +
<description of implementation>
  +
  +
== Problem 35 ==
  +
  +
<Problem description>
  +
  +
<pre>
  +
Example:
  +
<example in lisp>
  +
  +
Example in Haskell:
  +
<example in Haskell>
  +
</pre>
  +
  +
Solution:
  +
<haskell>
  +
<solution in haskell>
  +
</haskell>
  +
  +
<description of implementation>
  +
  +
== Problem 36 ==
  +
  +
<Problem description>
  +
  +
<pre>
  +
Example:
  +
<example in lisp>
  +
  +
Example in Haskell:
  +
<example in Haskell>
  +
</pre>
  +
  +
Solution:
  +
<haskell>
  +
<solution in haskell>
  +
</haskell>
  +
  +
<description of implementation>
  +
  +
== Problem 37 ==
  +
  +
<Problem description>
  +
  +
<pre>
  +
Example:
  +
<example in lisp>
  +
  +
Example in Haskell:
  +
<example in Haskell>
  +
</pre>
  +
  +
Solution:
  +
<haskell>
  +
<solution in haskell>
  +
</haskell>
  +
  +
<description of implementation>
  +
  +
== Problem 38 ==
  +
  +
<Problem description>
  +
  +
<pre>
  +
Example:
  +
<example in lisp>
  +
  +
Example in Haskell:
  +
<example in Haskell>
  +
</pre>
  +
  +
Solution:
  +
<haskell>
  +
<solution in haskell>
  +
</haskell>
  +
  +
<description of implementation>
  +
  +
== Problem 39 ==
  +
  +
<Problem description>
  +
  +
<pre>
  +
Example:
  +
<example in lisp>
  +
  +
Example in Haskell:
  +
<example in Haskell>
  +
</pre>
  +
  +
Solution:
  +
<haskell>
  +
<solution in haskell>
  +
</haskell>
  +
  +
<description of implementation>
  +
  +
== Problem 40 ==
  +
  +
<Problem description>
  +
  +
<pre>
  +
Example:
  +
<example in lisp>
  +
  +
Example in Haskell:
  +
<example in Haskell>
  +
</pre>
  +
  +
Solution:
  +
<haskell>
  +
<solution in haskell>
  +
</haskell>
  +
  +
<description of implementation>
  +
  +
== Problem n ==
  +
  +
<Problem description>
  +
  +
<pre>
  +
Example:
  +
<example in lisp>
  +
  +
Example in Haskell:
  +
<example in Haskell>
  +
</pre>
  +
  +
Solution:
  +
<haskell>
  +
<solution in haskell>
  +
</haskell>
  +
  +
<description of implementation>
  +
  +
== Problem n ==
  +
  +
<Problem description>
  +
  +
<pre>
  +
Example:
  +
<example in lisp>
  +
  +
Example in Haskell:
  +
<example in Haskell>
  +
</pre>
  +
  +
Solution:
  +
<haskell>
  +
<solution in haskell>
  +
</haskell>
  +
  +
<description of implementation>
  +
  +
== Problem n ==
  +
  +
<Problem description>
  +
  +
<pre>
  +
Example:
  +
<example in lisp>
  +
  +
Example in Haskell:
  +
<example in Haskell>
  +
</pre>
  +
  +
Solution:
  +
<haskell>
  +
<solution in haskell>
  +
</haskell>
  +
  +
<description of implementation>
  +
  +
== Problem n ==
  +
  +
<Problem description>
  +
  +
<pre>
  +
Example:
  +
<example in lisp>
  +
  +
Example in Haskell:
  +
<example in Haskell>
  +
</pre>
  +
  +
Solution:
  +
<haskell>
  +
<solution in haskell>
  +
</haskell>
  +
  +
<description of implementation>
  +
  +
== Problem n ==
  +
  +
<Problem description>
  +
  +
<pre>
  +
Example:
  +
<example in lisp>
  +
  +
Example in Haskell:
  +
<example in Haskell>
  +
</pre>
  +
  +
Solution:
  +
<haskell>
  +
<solution in haskell>
  +
</haskell>
  +
  +
<description of implementation>
  +
  +
== Problem n ==
  +
  +
<Problem description>
  +
  +
<pre>
  +
Example:
  +
<example in lisp>
  +
  +
Example in Haskell:
  +
<example in Haskell>
  +
</pre>
  +
  +
Solution:
  +
<haskell>
  +
<solution in haskell>
  +
</haskell>
  +
  +
<description of implementation>
  +
  +
== Problem n ==
  +
  +
<Problem description>
  +
  +
<pre>
  +
Example:
  +
<example in lisp>
  +
  +
Example in Haskell:
  +
<example in Haskell>
  +
</pre>
  +
  +
Solution:
  +
<haskell>
  +
<solution in haskell>
  +
</haskell>
  +
  +
<description of implementation>
  +
  +
== Problem n ==
  +
  +
<Problem description>
  +
  +
<pre>
  +
Example:
  +
<example in lisp>
  +
  +
Example in Haskell:
  +
<example in Haskell>
  +
</pre>
  +
  +
Solution:
  +
<haskell>
  +
<solution in haskell>
  +
</haskell>
  +
  +
<description of implementation>
  +
  +
== Problem n ==
  +
  +
<Problem description>
  +
  +
<pre>
  +
Example:
  +
<example in lisp>
  +
  +
Example in Haskell:
  +
<example in Haskell>
  +
</pre>
  +
  +
Solution:
  +
<haskell>
  +
<solution in haskell>
  +
</haskell>
  +
  +
<description of implementation>
  +
  +
== Problem n ==
  +
  +
<Problem description>
  +
  +
<pre>
  +
Example:
  +
<example in lisp>
  +
  +
Example in Haskell:
  +
<example in Haskell>
  +
</pre>
  +
  +
Solution:
  +
<haskell>
  +
<solution in haskell>
  +
</haskell>
  +
  +
<description of implementation>
  +
  +
== Problem n ==
  +
  +
<Problem description>
  +
  +
<pre>
  +
Example:
  +
<example in lisp>
  +
  +
Example in Haskell:
  +
<example in Haskell>
  +
</pre>
  +
  +
Solution:
  +
<haskell>
  +
<solution in haskell>
  +
</haskell>
  +
  +
<description of implementation>
  +
  +
== Problem n ==
  +
  +
<Problem description>
  +
  +
<pre>
  +
Example:
  +
<example in lisp>
  +
  +
Example in Haskell:
  +
<example in Haskell>
  +
</pre>
  +
  +
Solution:
  +
<haskell>
  +
<solution in haskell>
  +
</haskell>
  +
  +
<description of implementation>
  +
  +
== Problem n ==
  +
  +
<Problem description>
  +
  +
<pre>
  +
Example:
  +
<example in lisp>
  +
  +
Example in Haskell:
  +
<example in Haskell>
  +
</pre>
  +
  +
Solution:
  +
<haskell>
  +
<solution in haskell>
  +
</haskell>
  +
  +
<description of implementation>
  +
  +
== Problem n ==
  +
  +
<Problem description>
  +
  +
<pre>
  +
Example:
  +
<example in lisp>
  +
  +
Example in Haskell:
  +
<example in Haskell>
  +
</pre>
  +
  +
Solution:
  +
<haskell>
  +
<solution in haskell>
  +
</haskell>
  +
  +
<description of implementation>
  +
  +
== Problem n ==
  +
  +
<Problem description>
  +
  +
<pre>
  +
Example:
  +
<example in lisp>
  +
  +
Example in Haskell:
  +
<example in Haskell>
  +
</pre>
  +
  +
Solution:
  +
<haskell>
  +
<solution in haskell>
  +
</haskell>
  +
  +
<description of implementation>
  +
  +
== Problem n ==
  +
  +
<Problem description>
  +
  +
<pre>
  +
Example:
  +
<example in lisp>
  +
  +
Example in Haskell:
  +
<example in Haskell>
  +
</pre>
  +
  +
Solution:
  +
<haskell>
  +
<solution in haskell>
  +
</haskell>
  +
  +
<description of implementation>
  +
  +
== Problem n ==
  +
  +
<Problem description>
  +
  +
<pre>
  +
Example:
  +
<example in lisp>
  +
  +
Example in Haskell:
  +
<example in Haskell>
  +
</pre>
  +
  +
Solution:
  +
<haskell>
  +
<solution in haskell>
  +
</haskell>
  +
  +
<description of implementation>
  +
  +
== Problem n ==
  +
  +
<Problem description>
  +
  +
<pre>
  +
Example:
  +
<example in lisp>
  +
  +
Example in Haskell:
  +
<example in Haskell>
  +
</pre>
  +
  +
Solution:
  +
<haskell>
  +
<solution in haskell>
  +
</haskell>
  +
  +
<description of implementation>
  +
  +
== Problem n ==
  +
  +
<Problem description>
  +
  +
<pre>
  +
Example:
  +
<example in lisp>
  +
  +
Example in Haskell:
  +
<example in Haskell>
  +
</pre>
  +
  +
Solution:
  +
<haskell>
  +
<solution in haskell>
  +
</haskell>
  +
  +
<description of implementation>
  +
  +
== Problem n ==
  +
  +
<Problem description>
  +
  +
<pre>
  +
Example:
  +
<example in lisp>
  +
  +
Example in Haskell:
  +
<example in Haskell>
  +
</pre>
  +
  +
Solution:
  +
<haskell>
  +
<solution in haskell>
  +
</haskell>
  +
  +
<description of implementation>
  +
  +
== Problem n ==
  +
  +
<Problem description>
  +
  +
<pre>
  +
Example:
  +
<example in lisp>
  +
  +
Example in Haskell:
  +
<example in Haskell>
  +
</pre>
  +
  +
Solution:
  +
<haskell>
  +
<solution in haskell>
  +
</haskell>
  +
  +
<description of implementation>
  +
  +
== Problem n ==
  +
  +
<Problem description>
  +
  +
<pre>
  +
Example:
  +
<example in lisp>
  +
  +
Example in Haskell:
  +
<example in Haskell>
  +
</pre>
  +
  +
Solution:
  +
<haskell>
  +
<solution in haskell>
  +
</haskell>
  +
  +
<description of implementation>
  +
  +
== Problem n ==
  +
  +
<Problem description>
  +
  +
<pre>
  +
Example:
  +
<example in lisp>
  +
  +
Example in Haskell:
  +
<example in Haskell>
  +
</pre>
  +
  +
Solution:
  +
<haskell>
  +
<solution in haskell>
  +
</haskell>
  +
  +
<description of implementation>
  +
  +
== Problem n ==
  +
  +
<Problem description>
  +
  +
<pre>
  +
Example:
  +
<example in lisp>
  +
  +
Example in Haskell:
  +
<example in Haskell>
  +
</pre>
  +
  +
Solution:
  +
<haskell>
  +
<solution in haskell>
  +
</haskell>
  +
  +
<description of implementation>
  +
  +
== Problem n ==
  +
  +
<Problem description>
  +
  +
<pre>
  +
Example:
  +
<example in lisp>
  +
  +
Example in Haskell:
  +
<example in Haskell>
  +
</pre>
  +
  +
Solution:
  +
<haskell>
  +
<solution in haskell>
  +
</haskell>
  +
  +
<description of implementation>
  +
  +
== Problem n ==
  +
  +
<Problem description>
  +
  +
<pre>
  +
Example:
  +
<example in lisp>
  +
  +
Example in Haskell:
  +
<example in Haskell>
  +
</pre>
  +
  +
Solution:
  +
<haskell>
  +
<solution in haskell>
  +
</haskell>
  +
  +
<description of implementation>
  +
  +
== Problem n ==
  +
  +
<Problem description>
  +
  +
<pre>
  +
Example:
  +
<example in lisp>
  +
  +
Example in Haskell:
  +
<example in Haskell>
  +
</pre>
  +
  +
Solution:
  +
<haskell>
  +
<solution in haskell>
  +
</haskell>
  +
  +
<description of implementation>
  +
  +
== Problem n ==
  +
  +
<Problem description>
  +
  +
<pre>
  +
Example:
  +
<example in lisp>
  +
  +
Example in Haskell:
  +
<example in Haskell>
  +
</pre>
  +
  +
Solution:
  +
<haskell>
  +
<solution in haskell>
  +
</haskell>
  +
  +
<description of implementation>
  +
  +
== Problem n ==
  +
  +
<Problem description>
  +
  +
<pre>
  +
Example:
  +
<example in lisp>
  +
  +
Example in Haskell:
  +
<example in Haskell>
  +
</pre>
  +
  +
Solution:
  +
<haskell>
  +
<solution in haskell>
  +
</haskell>
  +
  +
<description of implementation>
  +
  +
== Problem n ==
  +
  +
<Problem description>
  +
  +
<pre>
  +
Example:
  +
<example in lisp>
  +
  +
Example in Haskell:
  +
<example in Haskell>
  +
</pre>
  +
  +
Solution:
  +
<haskell>
  +
<solution in haskell>
  +
</haskell>
  +
  +
<description of implementation>
  +
  +
== Problem n ==
  +
  +
<Problem description>
  +
  +
<pre>
  +
Example:
  +
<example in lisp>
  +
  +
Example in Haskell:
  +
<example in Haskell>
  +
</pre>
  +
  +
Solution:
  +
<haskell>
  +
<solution in haskell>
  +
</haskell>
  +
  +
<description of implementation>
  +
  +
== Problem n ==
  +
  +
<Problem description>
  +
  +
<pre>
  +
Example:
  +
<example in lisp>
  +
  +
Example in Haskell:
  +
<example in Haskell>
  +
</pre>
  +
  +
Solution:
  +
<haskell>
  +
<solution in haskell>
  +
</haskell>
  +
  +
<description of implementation>
  +
  +
== Problem n ==
  +
  +
<Problem description>
  +
  +
<pre>
  +
Example:
  +
<example in lisp>
  +
  +
Example in Haskell:
  +
<example in Haskell>
  +
</pre>
  +
  +
Solution:
  +
<haskell>
  +
<solution in haskell>
  +
</haskell>
  +
  +
<description of implementation>
  +
  +
== Problem n ==
  +
  +
<Problem description>
  +
  +
<pre>
  +
Example:
  +
<example in lisp>
  +
  +
Example in Haskell:
  +
<example in Haskell>
  +
</pre>
  +
  +
Solution:
  +
<haskell>
  +
<solution in haskell>
  +
</haskell>
  +
  +
<description of implementation>
  +
  +
== Problem n ==
  +
  +
<Problem description>
  +
  +
<pre>
  +
Example:
  +
<example in lisp>
  +
  +
Example in Haskell:
  +
<example in Haskell>
  +
</pre>
  +
  +
Solution:
  +
<haskell>
  +
<solution in haskell>
  +
</haskell>
  +
  +
<description of implementation>
  +
  +
== Problem n ==
  +
  +
<Problem description>
  +
  +
<pre>
  +
Example:
  +
<example in lisp>
  +
  +
Example in Haskell:
  +
<example in Haskell>
  +
</pre>
  +
  +
Solution:
  +
<haskell>
  +
<solution in haskell>
  +
</haskell>
  +
  +
<description of implementation>
  +
  +
== Problem n ==
  +
  +
<Problem description>
  +
  +
<pre>
  +
Example:
  +
<example in lisp>
  +
  +
Example in Haskell:
  +
<example in Haskell>
  +
</pre>
  +
  +
Solution:
  +
<haskell>
  +
<solution in haskell>
  +
</haskell>
  +
  +
<description of implementation>
  +
  +
== Problem n ==
  +
  +
<Problem description>
  +
  +
<pre>
  +
Example:
  +
<example in lisp>
  +
  +
Example in Haskell:
  +
<example in Haskell>
  +
</pre>
  +
  +
Solution:
  +
<haskell>
  +
<solution in haskell>
  +
</haskell>
  +
  +
<description of implementation>
  +
  +
== Problem n ==
  +
  +
<Problem description>
  +
  +
<pre>
  +
Example:
  +
<example in lisp>
  +
  +
Example in Haskell:
  +
<example in Haskell>
  +
</pre>
  +
  +
Solution:
  +
<haskell>
  +
<solution in haskell>
  +
</haskell>
  +
  +
<description of implementation>
  +
  +
== Problem n ==
  +
  +
<Problem description>
  +
  +
<pre>
  +
Example:
  +
<example in lisp>
  +
  +
Example in Haskell:
  +
<example in Haskell>
  +
</pre>
  +
  +
Solution:
  +
<haskell>
  +
<solution in haskell>
  +
</haskell>
  +
  +
<description of implementation>
  +
  +
== Problem n ==
  +
  +
<Problem description>
  +
  +
<pre>
  +
Example:
  +
<example in lisp>
  +
  +
Example in Haskell:
  +
<example in Haskell>
  +
</pre>
  +
  +
Solution:
  +
<haskell>
  +
<solution in haskell>
  +
</haskell>
  +
  +
<description of implementation>
  +
  +
== Problem n ==
  +
  +
<Problem description>
  +
  +
<pre>
  +
Example:
  +
<example in lisp>
  +
  +
Example in Haskell:
  +
<example in Haskell>
  +
</pre>
  +
  +
Solution:
  +
<haskell>
  +
<solution in haskell>
  +
</haskell>
  +
  +
<description of implementation>
  +
  +
== Problem n ==
  +
  +
<Problem description>
  +
  +
<pre>
  +
Example:
  +
<example in lisp>
  +
  +
Example in Haskell:
  +
<example in Haskell>
  +
</pre>
  +
  +
Solution:
  +
<haskell>
  +
<solution in haskell>
  +
</haskell>
  +
  +
<description of implementation>
  +
  +
== Problem n ==
  +
  +
<Problem description>
  +
  +
<pre>
  +
Example:
  +
<example in lisp>
  +
  +
Example in Haskell:
  +
<example in Haskell>
  +
</pre>
  +
  +
Solution:
  +
<haskell>
  +
<solution in haskell>
  +
</haskell>
  +
  +
<description of implementation>
  +
  +
== Problem n ==
  +
  +
<Problem description>
  +
  +
<pre>
  +
Example:
  +
<example in lisp>
  +
  +
Example in Haskell:
  +
<example in Haskell>
  +
</pre>
  +
  +
Solution:
  +
<haskell>
  +
<solution in haskell>
  +
</haskell>
  +
  +
<description of implementation>
  +
  +
== Problem n ==
  +
  +
<Problem description>
  +
  +
<pre>
  +
Example:
  +
<example in lisp>
  +
  +
Example in Haskell:
  +
<example in Haskell>
  +
</pre>
  +
  +
Solution:
  +
<haskell>
  +
<solution in haskell>
  +
</haskell>
  +
  +
<description of implementation>
  +
  +
== Problem n ==
  +
  +
<Problem description>
  +
  +
<pre>
  +
Example:
  +
<example in lisp>
  +
  +
Example in Haskell:
  +
<example in Haskell>
  +
</pre>
  +
  +
Solution:
  +
<haskell>
  +
<solution in haskell>
  +
</haskell>
  +
  +
<description of implementation>
  +
  +
== Problem n ==
  +
  +
<Problem description>
  +
  +
<pre>
  +
Example:
  +
<example in lisp>
  +
  +
Example in Haskell:
  +
<example in Haskell>
  +
</pre>
  +
  +
Solution:
  +
<haskell>
  +
<solution in haskell>
  +
</haskell>
  +
  +
<description of implementation>
  +
  +
== Problem n ==
  +
  +
<Problem description>
  +
  +
<pre>
  +
Example:
  +
<example in lisp>
  +
  +
Example in Haskell:
  +
<example in Haskell>
  +
</pre>
  +
  +
Solution:
  +
<haskell>
  +
<solution in haskell>
  +
</haskell>
  +
  +
<description of implementation>
  +
  +
== Problem n ==
  +
  +
<Problem description>
  +
  +
<pre>
  +
Example:
  +
<example in lisp>
  +
  +
Example in Haskell:
  +
<example in Haskell>
  +
</pre>
  +
  +
Solution:
  +
<haskell>
  +
<solution in haskell>
  +
</haskell>
  +
  +
<description of implementation>
  +
  +
== Problem n ==
  +
  +
<Problem description>
  +
  +
<pre>
  +
Example:
  +
<example in lisp>
  +
  +
Example in Haskell:
  +
<example in Haskell>
  +
</pre>
  +
  +
Solution:
  +
<haskell>
  +
<solution in haskell>
  +
</haskell>
  +
  +
<description of implementation>
  +
  +
== Problem n ==
  +
  +
<Problem description>
  +
  +
<pre>
  +
Example:
  +
<example in lisp>
  +
  +
Example in Haskell:
  +
<example in Haskell>
  +
</pre>
  +
  +
Solution:
  +
<haskell>
  +
<solution in haskell>
  +
</haskell>
  +
  +
<description of implementation>
  +
  +
== Problem n ==
  +
  +
<Problem description>
  +
  +
<pre>
  +
Example:
  +
<example in lisp>
  +
  +
Example in Haskell:
  +
<example in Haskell>
  +
</pre>
  +
  +
Solution:
  +
<haskell>
  +
<solution in haskell>
  +
</haskell>
  +
  +
<description of implementation>
  +
  +
== Problem n ==
  +
  +
<Problem description>
  +
  +
<pre>
  +
Example:
  +
<example in lisp>
  +
  +
Example in Haskell:
  +
<example in Haskell>
  +
</pre>
  +
  +
Solution:
  +
<haskell>
  +
<solution in haskell>
  +
</haskell>
  +
  +
<description of implementation>
  +
  +
== Problem n ==
  +
  +
<Problem description>
  +
  +
<pre>
  +
Example:
  +
<example in lisp>
  +
  +
Example in Haskell:
  +
<example in Haskell>
  +
</pre>
  +
  +
Solution:
  +
<haskell>
  +
<solution in haskell>
  +
</haskell>
  +
  +
<description of implementation>
  +
  +
== Problem n ==
  +
  +
<Problem description>
  +
  +
<pre>
  +
Example:
  +
<example in lisp>
  +
  +
Example in Haskell:
  +
<example in Haskell>
  +
</pre>
  +
  +
Solution:
  +
<haskell>
  +
<solution in haskell>
  +
</haskell>
  +
  +
<description of implementation>
  +
  +
== Problem n ==
  +
  +
<Problem description>
  +
  +
<pre>
  +
Example:
  +
<example in lisp>
  +
  +
Example in Haskell:
  +
<example in Haskell>
  +
</pre>
  +
  +
Solution:
  +
<haskell>
  +
<solution in haskell>
  +
</haskell>
  +
  +
<description of implementation>
  +
  +
== Problem n ==
  +
  +
<Problem description>
  +
  +
<pre>
  +
Example:
  +
<example in lisp>
  +
  +
Example in Haskell:
  +
<example in Haskell>
  +
</pre>
  +
  +
Solution:
  +
<haskell>
  +
<solution in haskell>
  +
</haskell>
  +
  +
<description of implementation>
  +
  +
== Problem n ==
  +
  +
<Problem description>
  +
  +
<pre>
  +
Example:
  +
<example in lisp>
  +
  +
Example in Haskell:
  +
<example in Haskell>
  +
</pre>
  +
  +
Solution:
  +
<haskell>
  +
<solution in haskell>
  +
</haskell>
  +
  +
<description of implementation>
 
 
 
== Problem n ==
 
== Problem n ==
Line 175: Line 1,904:
 
Solution:
 
Solution:
 
<haskell>
 
<haskell>
<solution in haskell
+
<solution in haskell>
 
</haskell>
 
</haskell>
   

Revision as of 06:05, 12 December 2006

These are Haskell translations of Ninety Nine Lisp Problems.

Problem 1

(*) Find the last box of a list.

Example:
* (my-last '(a b c d))
(D)

This is "last" in Prelude, which is defined as:

last :: [a] -> a
last [x] = x
last (_:xs) = last xs

Problem 2

(*) Find the last but one box of a list.

Example:
* (my-but-last '(a b c d))
(C D)

This can be done by dropping all but the last two elements of a list:

myButLast :: [a] -> [a]
myButLast list = drop ((length list) - 2) list

Problem 3

(*) Find the K'th element of a list. The first element in the list is number 1.

Example:
* (element-at '(a b c d e) 3)
C

This is (almost) the infix operator !! in Prelude, which is defined as:

(!!)                :: [a] -> Int -> a
(x:_)  !! 0         =  x
(_:xs) !! n         =  xs !! (n-1)

Except this doesn't quite work, because !! is zero-indexed, and element-at should be one-indexed. So:

elementAt :: [a] -> Int -> a
elementAt list i = list !! (i-1)

Problem 4

(*) Find the number of elements of a list.

This is "length" in Prelude, which is defined as:

length           :: [a] -> Int
length []        =  0
length (_:l)     =  1 + length l

Problem 5

(*) Reverse a list.

This is "reverse" in Prelude, which is defined as:

reverse          :: [a] -> [a]
reverse          =  foldl (flip (:)) []

The standard definition is concise, but not very readable. Another way to define reverse is:

reverse :: [a] -> [a]
reverse [] = []
reverse (x:xs) = reverse xs ++ [x]

Problem 6

(*) Find out whether a list is a palindrome. A palindrome can be read forward or backward; e.g. (x a m a x).

This is trivial, because we can use reverse:

isPalindrome :: (Eq a) => [a] -> Bool
isPalindrome xs = xs == (reverse xs)

Problem 7

(**) Flatten a nested list structure.

Transform a list, possibly holding lists as elements into a `flat' list by replacing each list with its elements (recursively).

Example:
* (my-flatten '(a (b (c d) e)))
(A B C D E)

This is tricky, because lists in Haskell are homogeneous. [1, [2, [3, 4], 5]] is a type error. We have to devise some way of represent a list that may (or may not) be nested:

data NestedList a = Elem a | List [NestedList a]

flatten :: NestedList a -> [a]
flatten (Elem x) = [x]
flatten (List []) = []
flatten (List (x:xs)) = flatten x ++ flatten (List xs)

Our NestedList datatype is either a single element of some type (Elem a), or a list of NestedLists of the same type. (List [NestedList a]). Let's try it out in ghci:

*Main> flatten (Elem 5)
[5]
*Main> flatten (List [Elem 1, List [Elem 2, List [Elem 3, Elem 4], Elem 5]])
[1,2,3,4,5]
*Main> flatten (List [])
[]

Problem 8

(**) Eliminate consecutive duplicates of list elements.

If a list contains repeated elements they should be replaced with a single copy of the element. The order of the elements should not be changed.

Example:
* (compress '(a a a a b c c a a d e e e e))
(A B C A D E)

Example in Haskell:
*Main> compress ['a','a','a','a','b','c','c','a','a','d','e','e','e','e']
['a','b','c','a','d','e']

Solution:

compress = map head . group

We simply group equal values together (group), then take the head of each.

Problem 9

<Problem description>

Example:
<example in lisp>

Example in Haskell:
<example in Haskell>

Solution:

<solution in haskell>

<description of implementation>

Problem 10

<Problem description>

Example:
<example in lisp>

Example in Haskell:
<example in Haskell>

Solution:

<solution in haskell>

<description of implementation>

Problem 11

<Problem description>

Example:
<example in lisp>

Example in Haskell:
<example in Haskell>

Solution:

<solution in haskell>

<description of implementation>

Problem 12

<Problem description>

Example:
<example in lisp>

Example in Haskell:
<example in Haskell>

Solution:

<solution in haskell>

<description of implementation>

Problem 13

<Problem description>

Example:
<example in lisp>

Example in Haskell:
<example in Haskell>

Solution:

<solution in haskell>

<description of implementation>

Problem 14

<Problem description>

Example:
<example in lisp>

Example in Haskell:
<example in Haskell>

Solution:

<solution in haskell>

<description of implementation>

Problem 15

<Problem description>

Example:
<example in lisp>

Example in Haskell:
<example in Haskell>

Solution:

<solution in haskell>

<description of implementation>

Problem 16

<Problem description>

Example:
<example in lisp>

Example in Haskell:
<example in Haskell>

Solution:

<solution in haskell>

<description of implementation>

Problem 17

<Problem description>

Example:
<example in lisp>

Example in Haskell:
<example in Haskell>

Solution:

<solution in haskell>

<description of implementation>

Problem 18

<Problem description>

Example:
<example in lisp>

Example in Haskell:
<example in Haskell>

Solution:

<solution in haskell>

<description of implementation>

Problem 19

<Problem description>

Example:
<example in lisp>

Example in Haskell:
<example in Haskell>

Solution:

<solution in haskell>

<description of implementation>

Problem 20

<Problem description>

Example:
<example in lisp>

Example in Haskell:
<example in Haskell>

Solution:

<solution in haskell>

<description of implementation>

Problem 21

<Problem description>

Example:
<example in lisp>

Example in Haskell:
<example in Haskell>

Solution:

<solution in haskell>

<description of implementation>

Problem 22

<Problem description>

Example:
<example in lisp>

Example in Haskell:
<example in Haskell>

Solution:

<solution in haskell>

<description of implementation>

Problem 23

<Problem description>

Example:
<example in lisp>

Example in Haskell:
<example in Haskell>

Solution:

<solution in haskell>

<description of implementation>

Problem 24

<Problem description>

Example:
<example in lisp>

Example in Haskell:
<example in Haskell>

Solution:

<solution in haskell>

<description of implementation>

Problem 25

<Problem description>

Example:
<example in lisp>

Example in Haskell:
<example in Haskell>

Solution:

<solution in haskell>

<description of implementation>

Problem 26

<Problem description>

Example:
<example in lisp>

Example in Haskell:
<example in Haskell>

Solution:

<solution in haskell>

<description of implementation>

Problem 27

<Problem description>

Example:
<example in lisp>

Example in Haskell:
<example in Haskell>

Solution:

<solution in haskell>

<description of implementation>

Problem 28

<Problem description>

Example:
<example in lisp>

Example in Haskell:
<example in Haskell>

Solution:

<solution in haskell>

<description of implementation>

Problem 29

<Problem description>

Example:
<example in lisp>

Example in Haskell:
<example in Haskell>

Solution:

<solution in haskell>

<description of implementation>

Problem 30

<Problem description>

Example:
<example in lisp>

Example in Haskell:
<example in Haskell>

Solution:

<solution in haskell>

<description of implementation>

Problem 31

<Problem description>

Example:
<example in lisp>

Example in Haskell:
<example in Haskell>

Solution:

<solution in haskell>

<description of implementation>

Problem 32

<Problem description>

Example:
<example in lisp>

Example in Haskell:
<example in Haskell>

Solution:

<solution in haskell>

<description of implementation>

Problem 33

<Problem description>

Example:
<example in lisp>

Example in Haskell:
<example in Haskell>

Solution:

<solution in haskell>

<description of implementation>

Problem 34

<Problem description>

Example:
<example in lisp>

Example in Haskell:
<example in Haskell>

Solution:

<solution in haskell>

<description of implementation>

Problem 35

<Problem description>

Example:
<example in lisp>

Example in Haskell:
<example in Haskell>

Solution:

<solution in haskell>

<description of implementation>

Problem 36

<Problem description>

Example:
<example in lisp>

Example in Haskell:
<example in Haskell>

Solution:

<solution in haskell>

<description of implementation>

Problem 37

<Problem description>

Example:
<example in lisp>

Example in Haskell:
<example in Haskell>

Solution:

<solution in haskell>

<description of implementation>

Problem 38

<Problem description>

Example:
<example in lisp>

Example in Haskell:
<example in Haskell>

Solution:

<solution in haskell>

<description of implementation>

Problem 39

<Problem description>

Example:
<example in lisp>

Example in Haskell:
<example in Haskell>

Solution:

<solution in haskell>

<description of implementation>

Problem 40

<Problem description>

Example:
<example in lisp>

Example in Haskell:
<example in Haskell>

Solution:

<solution in haskell>

<description of implementation>

Problem n

<Problem description>

Example:
<example in lisp>

Example in Haskell:
<example in Haskell>

Solution:

<solution in haskell>

<description of implementation>

Problem n

<Problem description>

Example:
<example in lisp>

Example in Haskell:
<example in Haskell>

Solution:

<solution in haskell>

<description of implementation>

Problem n

<Problem description>

Example:
<example in lisp>

Example in Haskell:
<example in Haskell>

Solution:

<solution in haskell>

<description of implementation>

Problem n

<Problem description>

Example:
<example in lisp>

Example in Haskell:
<example in Haskell>

Solution:

<solution in haskell>

<description of implementation>

Problem n

<Problem description>

Example:
<example in lisp>

Example in Haskell:
<example in Haskell>

Solution:

<solution in haskell>

<description of implementation>

Problem n

<Problem description>

Example:
<example in lisp>

Example in Haskell:
<example in Haskell>

Solution:

<solution in haskell>

<description of implementation>

Problem n

<Problem description>

Example:
<example in lisp>

Example in Haskell:
<example in Haskell>

Solution:

<solution in haskell>

<description of implementation>

Problem n

<Problem description>

Example:
<example in lisp>

Example in Haskell:
<example in Haskell>

Solution:

<solution in haskell>

<description of implementation>

Problem n

<Problem description>

Example:
<example in lisp>

Example in Haskell:
<example in Haskell>

Solution:

<solution in haskell>

<description of implementation>

Problem n

<Problem description>

Example:
<example in lisp>

Example in Haskell:
<example in Haskell>

Solution:

<solution in haskell>

<description of implementation>

Problem n

<Problem description>

Example:
<example in lisp>

Example in Haskell:
<example in Haskell>

Solution:

<solution in haskell>

<description of implementation>

Problem n

<Problem description>

Example:
<example in lisp>

Example in Haskell:
<example in Haskell>

Solution:

<solution in haskell>

<description of implementation>

Problem n

<Problem description>

Example:
<example in lisp>

Example in Haskell:
<example in Haskell>

Solution:

<solution in haskell>

<description of implementation>

Problem n

<Problem description>

Example:
<example in lisp>

Example in Haskell:
<example in Haskell>

Solution:

<solution in haskell>

<description of implementation>

Problem n

<Problem description>

Example:
<example in lisp>

Example in Haskell:
<example in Haskell>

Solution:

<solution in haskell>

<description of implementation>

Problem n

<Problem description>

Example:
<example in lisp>

Example in Haskell:
<example in Haskell>

Solution:

<solution in haskell>

<description of implementation>

Problem n

<Problem description>

Example:
<example in lisp>

Example in Haskell:
<example in Haskell>

Solution:

<solution in haskell>

<description of implementation>

Problem n

<Problem description>

Example:
<example in lisp>

Example in Haskell:
<example in Haskell>

Solution:

<solution in haskell>

<description of implementation>

Problem n

<Problem description>

Example:
<example in lisp>

Example in Haskell:
<example in Haskell>

Solution:

<solution in haskell>

<description of implementation>

Problem n

<Problem description>

Example:
<example in lisp>

Example in Haskell:
<example in Haskell>

Solution:

<solution in haskell>

<description of implementation>

Problem n

<Problem description>

Example:
<example in lisp>

Example in Haskell:
<example in Haskell>

Solution:

<solution in haskell>

<description of implementation>

Problem n

<Problem description>

Example:
<example in lisp>

Example in Haskell:
<example in Haskell>

Solution:

<solution in haskell>

<description of implementation>

Problem n

<Problem description>

Example:
<example in lisp>

Example in Haskell:
<example in Haskell>

Solution:

<solution in haskell>

<description of implementation>

Problem n

<Problem description>

Example:
<example in lisp>

Example in Haskell:
<example in Haskell>

Solution:

<solution in haskell>

<description of implementation>

Problem n

<Problem description>

Example:
<example in lisp>

Example in Haskell:
<example in Haskell>

Solution:

<solution in haskell>

<description of implementation>

Problem n

<Problem description>

Example:
<example in lisp>

Example in Haskell:
<example in Haskell>

Solution:

<solution in haskell>

<description of implementation>

Problem n

<Problem description>

Example:
<example in lisp>

Example in Haskell:
<example in Haskell>

Solution:

<solution in haskell>

<description of implementation>

Problem n

<Problem description>

Example:
<example in lisp>

Example in Haskell:
<example in Haskell>

Solution:

<solution in haskell>

<description of implementation>

Problem n

<Problem description>

Example:
<example in lisp>

Example in Haskell:
<example in Haskell>

Solution:

<solution in haskell>

<description of implementation>

Problem n

<Problem description>

Example:
<example in lisp>

Example in Haskell:
<example in Haskell>

Solution:

<solution in haskell>

<description of implementation>

Problem n

<Problem description>

Example:
<example in lisp>

Example in Haskell:
<example in Haskell>

Solution:

<solution in haskell>

<description of implementation>

Problem n

<Problem description>

Example:
<example in lisp>

Example in Haskell:
<example in Haskell>

Solution:

<solution in haskell>

<description of implementation>

Problem n

<Problem description>

Example:
<example in lisp>

Example in Haskell:
<example in Haskell>

Solution:

<solution in haskell>

<description of implementation>

Problem n

<Problem description>

Example:
<example in lisp>

Example in Haskell:
<example in Haskell>

Solution:

<solution in haskell>

<description of implementation>

Problem n

<Problem description>

Example:
<example in lisp>

Example in Haskell:
<example in Haskell>

Solution:

<solution in haskell>

<description of implementation>

Problem n

<Problem description>

Example:
<example in lisp>

Example in Haskell:
<example in Haskell>

Solution:

<solution in haskell>

<description of implementation>

Problem n

<Problem description>

Example:
<example in lisp>

Example in Haskell:
<example in Haskell>

Solution:

<solution in haskell>

<description of implementation>

Problem n

<Problem description>

Example:
<example in lisp>

Example in Haskell:
<example in Haskell>

Solution:

<solution in haskell>

<description of implementation>

Problem n

<Problem description>

Example:
<example in lisp>

Example in Haskell:
<example in Haskell>

Solution:

<solution in haskell>

<description of implementation>

Problem n

<Problem description>

Example:
<example in lisp>

Example in Haskell:
<example in Haskell>

Solution:

<solution in haskell>

<description of implementation>

Problem n

<Problem description>

Example:
<example in lisp>

Example in Haskell:
<example in Haskell>

Solution:

<solution in haskell>

<description of implementation>

Problem n

<Problem description>

Example:
<example in lisp>

Example in Haskell:
<example in Haskell>

Solution:

<solution in haskell>

<description of implementation>

Problem n

<Problem description>

Example:
<example in lisp>

Example in Haskell:
<example in Haskell>

Solution:

<solution in haskell>

<description of implementation>

Problem n

<Problem description>

Example:
<example in lisp>

Example in Haskell:
<example in Haskell>

Solution:

<solution in haskell>

<description of implementation>

Problem n

<Problem description>

Example:
<example in lisp>

Example in Haskell:
<example in Haskell>

Solution:

<solution in haskell>

<description of implementation>

Problem n

<Problem description>

Example:
<example in lisp>

Example in Haskell:
<example in Haskell>

Solution:

<solution in haskell>

<description of implementation>

Problem n

<Problem description>

Example:
<example in lisp>

Example in Haskell:
<example in Haskell>

Solution:

<solution in haskell>

<description of implementation>

Problem n

<Problem description>

Example:
<example in lisp>

Example in Haskell:
<example in Haskell>

Solution:

<solution in haskell>

<description of implementation>

Problem n

<Problem description>

Example:
<example in lisp>

Example in Haskell:
<example in Haskell>

Solution:

<solution in haskell>

<description of implementation>

Problem n

<Problem description>

Example:
<example in lisp>

Example in Haskell:
<example in Haskell>

Solution:

<solution in haskell>

<description of implementation>

Problem n

<Problem description>

Example:
<example in lisp>

Example in Haskell:
<example in Haskell>

Solution:

<solution in haskell>

<description of implementation>

Problem n

<Problem description>

Example:
<example in lisp>

Example in Haskell:
<example in Haskell>

Solution:

<solution in haskell>

<description of implementation>

Problem n

<Problem description>

Example:
<example in lisp>

Example in Haskell:
<example in Haskell>

Solution:

<solution in haskell>

<description of implementation>

Problem n

<Problem description>

Example:
<example in lisp>

Example in Haskell:
<example in Haskell>

Solution:

<solution in haskell>

<description of implementation>

Problem n

<Problem description>

Example:
<example in lisp>

Example in Haskell:
<example in Haskell>

Solution:

<solution in haskell>

<description of implementation>

Problem n

<Problem description>

Example:
<example in lisp>

Example in Haskell:
<example in Haskell>

Solution:

<solution in haskell>

<description of implementation>

Problem n

<Problem description>

Example:
<example in lisp>

Example in Haskell:
<example in Haskell>

Solution:

<solution in haskell>

<description of implementation>

Problem n

<Problem description>

Example:
<example in lisp>

Example in Haskell:
<example in Haskell>

Solution:

<solution in haskell>

<description of implementation>

Problem n

<Problem description>

Example:
<example in lisp>

Example in Haskell:
<example in Haskell>

Solution:

<solution in haskell>

<description of implementation>

Problem n

<Problem description>

Example:
<example in lisp>

Example in Haskell:
<example in Haskell>

Solution:

<solution in haskell>

<description of implementation>