Task 1: Registration Number

You are given a list of words and a random registration number.
Write a script to find all the words in the given list that has every
letter in the given registration number.

Example 1

  Input: @words = ('abc', 'abcd', 'bcd'), $reg = 'AB1 2CD'
  Output: ('abcd')

  The only word that matches every alphabets in the given registration number is 'abcd'.

Example 2

  Input: @words = ('job', 'james', 'bjorg'), $reg = '007 JB'
  Output: ('job', 'bjorg')

Example 3

  Input: @words = ('crack', 'road', 'rac'), $reg = 'C7 RA2'
  Output: ('crack', 'rac')

MY NOTES: I think the meaning is: form a set of all letters from the
registration.  Select all words that contain every member of the set.
That's easy.

GUEST LANGUAGE: As a bonus, I've had a go at translating ch-1.pl into C,
look in the C/ directory for that.


Task 2: Word Stickers

You are given a list of word stickers and a target word.
Write a script to find out how many word stickers is needed to make up
the given target word.

Example 1:

  Input: @stickers = ('perl','raku','python'), $word = 'peon'
  Output: 2

  We just need 2 stickers i.e. 'perl' and 'python'.
  'pe' from 'perl' and
  'on' from 'python' to get the target word.

Example 2:

  Input: @stickers = ('love','hate','angry'), $word = 'goat'
  Output: 3

  We need 3 stickers i.e. 'angry', 'love' and 'hate'.
  'g' from 'angry'
  'o' from 'love' and
  'at' from 'hate' to get the target word.

Example 3:

  Input: @stickers = ('come','nation','delta'), $word = 'accommodation'
  Output: 4

  We just need 2 stickers of 'come' and one each of 'nation' & 'delta'.
  'a' from 'delta'
  'ccommo' from 2 stickers 'come'
  'd' from the same sticker 'delta' and
  'ation' from 'nation' to get the target word.

Example 4:

  Input: @stickers = ('come','country','delta'), $word = 'accommodation'
  Output: 0

as there's no "i" in the inputs.


MY NOTES: ok, so the only tricky part is that each sticker may be used any
number of times (if any of it's letters remain in the word).  It will be
worth checking that every letter in the word is present in one or more stickers
before starting the main search process.

GUEST LANGUAGE: I will have a go at translating ch-2.pl into C tomorrow;
look in the C/ directory when that's done.