#!/usr/bin/perl

# https://theweeklychallenge.org/blog/perl-weekly-challenge-283/
# Task #2 > Changing Keys
#
# You are given an alphabetic string, $str, as typed by user.
#
# Write a script to find the number of times user had to change the key to type the given string. Changing key is defined as using a key different from the last used key. The shift and caps lock keys won’t be counted.
#
# Example 1
# Input: $str = 'pPeERrLl'
# Ouput: 3
#
# p -> P : 0 key change
# P -> e : 1 key change
# e -> E : 0 key change
# E -> R : 1 key change
# R -> r : 0 key change
# r -> L : 1 key change
# L -> l : 0 key change
#
# Example 2
# Input: $str = 'rRr'
# Ouput: 0
#
# Example 3
# Input: $str = 'GoO'
# Ouput: 1

use strict;
use warnings;
use feature 'say';

my $str = shift;

my @chars = map {lc} split //, $str;
my $count = grep { $chars[$_] ne $chars[$_ - 1] } 1 .. $#chars;
say $count;