Broken keys

You are given a $sentence and a list of broken @keys. Write a script to find out how many words can be typed fully.

Examples

Example 1
Input: $sentence = "Perl Weekly Challenge", 
     @keys = ('l', 'a')
Output: 0

Example 2
Input: $sentence = "Perl and Raku", 
     @keys = ('a')
Output: 1
Only Perl since the other word two words contain 'a' 
and can't be typed fully.

Example 3
Input: $sentence = "Well done Team PWC", 
     @keys = ('l', 'o')
Output: 2

Example 4
Input: $sentence = "The joys of polyglottism", 
     @keys = ('T')
Output: 2

Analysis

My solution consists essentially of two lines. The first is:

$sentence =~ s|$_|#|g for @keys;

which changes all the @keys characters into '#'.

The second is

$count += ($_ !~ m|#| ? 1 : 0) 
        for split(/ /, $sentence);

which splits $sentence into words and counts the ones that don't contain a '#'.

Note that example 4 above demonstrates that the matching of keys is case-independent, and I therefore lower-case both $sentence and @keys on input.

See also week 341 task 1

DIY tool with detailed task analysis is bonus. You are going to love it, I am confident.

This review may cover either or both challenges for this week.

I am sorry that the 'Try it' feature is currently working very slowly or not at all owing to some issue with my web hosting provider.

Try it 

Try running the script with any input:

Your $sentence =

example: this is not difficult

Your @keys =

example: f, s

⤡

#!/usr/bin/perl

# Blog: http://ccgi.campbellsmiths.force9.co.uk/challenge

use v5.26;    # The Weekly Challenge - 2024-06-24
use utf8;     # Week 275 - task 1 - Broken keys
use warnings; # Peter Campbell Smith
binmode STDOUT, ':utf8';

my ($sentence, @keys);

broken_keys('Perl Weekly Challenge', 'l', 'a');
broken_keys('The joys of polyglottism', 'T');
broken_keys('Write a script to find out how many words can be typed fully', 'i', 'o');
broken_keys('All cows eat grass', 'b', 'd', 'f', 'h', 'i');
broken_keys('Vitamins keep you healthy', 'v', 'k', 'u', 'y');

sub broken_keys {
    
    my ($sentence, @keys, $count);
    
    printf(qq[\nInput:  \$sentence = ('%s'), \@keys = ('%s')\n], $_[0], join(q[', '], @_[1 .. @_ - 1]));
    $sentence = lc(shift @_);
    push @keys, lc($_) for @_;
    
    # change any occurrences of keys to '#'
    $sentence =~ s|$_|#|g for @keys;
    
    # count the words which don't contain '#'
    $count += ($_ !~ m|#| ? 1 : 0) for split(/ /, $sentence);
    
    printf(qq[Output: %s\n], defined $count ? $count : 0);
}

8 lines of code

Output from script

Input:  $sentence = ('Perl Weekly Challenge'), @keys = ('l', 'a')
Output: 0

Input:  $sentence = ('The joys of polyglottism'), @keys = ('T')
Output: 2

Input:  $sentence = ('Write a script to find out how many words can be typed fully'), @keys = ('i', 'o')
Output: 6

Input:  $sentence = ('All cows eat grass'), @keys = ('b', 'd', 'f', 'h', 'i')
Output: 4

Input:  $sentence = ('Vitamins keep you healthy'), @keys = ('v', 'k', 'u', 'y')
Output: 0