Common prefix and suffix

Save all functions into the same file named presuffix.py.

1. Write the function common_prefix() that takes two strings each containing a word, and returns another string with the longest common prefix of these words.

   See the following examples:

   >>> common_prefix ('polihedron', 'politechnic')
   'poli'
   >>> common_prefix ('polihedron', 'poli')
   'poli'
   >>> common_prefix ('', '')
   ''
   >>> common_prefix ('program', 'algorithm')
   ''
   

   Note

   More tests are provided in the prefix.txt file.

2. Write the function common_suffix() that takes two strings each containing a word, and returns another string with the longest common suffix of these words.

   See the following examples:

   >>> common_suffix ('laicism', 'communism')
   'ism'
   >>> common_suffix ('singing', 'going')
   'ing'
   >>> common_suffix ('hello', 'bye')
   ''
   >>> common_suffix ('navigator', 'navigator')
   'navigator'
   >>> common_suffix ('incredible', 'edible')
   'edible'
   

   Note

   More tests are provided in the suffix.txt file.

Solutions

A solution of these functions is provided in the presuffix.py file.