Each week Mohammad S. Anwar sends out The Weekly Challenge, a chance for all of us to come up with solutions to two weekly tasks. My solutions are written in Python first, and then converted to Perl. It's a great way for us all to practice some coding.

Challenge, My solutions

Task 1: Separate Digits

Task

You are given an array of positive integers.

Write a script to separate the given array into single digits.

My solution

Two relatively straight forward tasks this week, so doesn't really need much explanation. For this task I can treat the integers as strings. Iterating a string will produce the individual characters. I then use a double for loop to flatten this to a single list.

solution = [ digit for i in ints for digit in i]

In Perl, I use the split method to get the individual digits of the number, and map to achieve this for all numbers.

my @solution = ( map { split // } @ints );

Examples

$ ./ch-1.py 1 34 5 6
(1, 3, 4, 5, 6)

$ ./ch-1.py 1 24 51 60
(1, 2, 4, 5, 1, 6, 0)

Task 2: Count Words

Task

You are given an array of words made up of alphabetic characters and a prefix.

Write a script to return the count of words that starts with the given prefix.

My solution

For this task, I pop the last item of the list, and assign this to the prefix variable. I then use the startswith() method on the string to count the number of words that start with the prefix.

solution = sum(1 for word in words if word.lower().startswith(prefix.lower()))

For the Perl solution, we can use the grep function to find words that start with the prefix.

    my @solution = grep { substr( lc $_, 0, $len ) eq lc($prefix) } @words;

Examples

$ ./ch-2.py pay attention practive attend at
2

$ ./ch-2.py janet julia java javascript ja
3