# Solutions by Abigail
## [Search Matrix](https://perlweeklychallenge.org/blog/perl-weekly-challenge-111/#TASK1)

> You are given 5x5 matrix filled with integers such that each row is
> sorted from left to right and the first integer of each row is greater
> than the last integer of the previous row.
>
> Write a script to find a given integer in the matrix using an
> efficient search algorithm.

### Notes
This challenge confuses me. We're basically asked to find a number
in a sorted list. Which in languages without hashes one would solve
with binary search (yielding an O (log N) solution), and in languages
with hashes you'd use a hash (yielding an O (1) (expected) time solution).
Sure, the hash takes linear preprocessing time, but since we're asked
to write a script, we're spending linear time reading in the data
anyway.

Perhaps the intend was a subroutine which takes a matrix and a target
number, but that was not what is being asked. The challenge explicitly
asks for *a script*, which means we have to spend a linear amount of 
time reading data anyway. So, that's what you get.

The only part where we use the fact we are given a matrix is for the
input: the first five lines are assumed to contain the matrix. The
rest of the input is taken as numbers to search for.

Only for language lacking hashes/maps/dictionaries/tables, we will
make use of the fact the input is sorted. For the majority of
languages, the fact input is sorted does not offer additional benefits.

For Perl, we make two implementations: one based on a hash, the
other using binary search.

### Solutions
* [AWK](awk/ch-1.awk)
* [Bash](bash/ch-1.sh)
* [C](c/ch-1.c)
* [Lua](lua/ch-1.lua)
* [Node.js](node/ch-1.js)
* [Pascal](pascal/ch-1.p)
* [Perl](perl/ch-1.pl)
* [Python](python/ch-1.py)
* [Ruby](ruby/ch-1.rb)

### Blog
[Perl Weekly Challenge 111: Search Matrix](https://abigail.github.io/HTML/Perl-Weekly-Challenge/week-111-1.html)

## [Ordered Letters](https://perlweeklychallenge.org/blog/perl-weekly-challenge-111/#TASK2)

> Given a word, you can sort its letters alphabetically (case insensitive).
> For example, 'beekeeper' becomes 'beeeeekpr' and 'dictionary' becomes
> 'acdiinorty'.
>
> Write a script to find the longest English words that don't change when
> their letters are sorted.

### Notes
We will grep the words from standard input which don't change
if they are sorted; these are the words which match the pattern
/^a*b*c*...z*$/i. We keep track of the longest word.

If course, there does not have to be a unique word. It will depend
on the word list used to search in. For instance, three different
word list I used give different results:

    infochimps.com     /usr/share/dict/words     enable.lst
    --------------     ---------------------     ----------
                                     Adelops
          aegilops
                                     alloquy
                                     beefily        beefily
                                     begorry
                                     billowy        billowy
                                     egilops

Only one of them has a unique longest word.

We will be reading a word list from standard input, and write
the longest word where the letters are in alphabetical order
to standard output. In case of ties, we print the first one found.


### Solutions
* [GNU AWK](awk/ch-2.gawk)
* [Bash](bash/ch-2.sh)
* [C](c/ch-2.c)
* [Lua](lua/ch-2.lua)
* [Node.js](node/ch-2.js)
* [Pascal](pascal/ch-2.p)
* [Perl](perl/ch-2.pl)
* [Python](python/ch-2.py)
* [Ruby](ruby/ch-2.rb)

### Blog
[Perl Weekly Challenge 111: Ordered Letters](https://abigail.github.io/HTML/Perl-Weekly-Challenge/week-111-2.html)