TWC323

Challenge Link

Task1

We increment and decrement x according to ++ or -- signs:

#!/usr/bin/env perl
use strict;
use warnings;

sub increment_decrement{
  my $x = 0;
  map{/\+\+/ ? $x++ : $x--} @{$_[0]};
  $x
}

printf "%d\n",increment_decrement(["--x","x++","x++"]);
printf "%d\n",increment_decrement(["x++","++x","x++"]);
printf "%d\n",increment_decrement(["x++","++x","--x","x--"]);

Task2

We calculate the tax amount according to the given formula:

#!/usr/bin/env perl
use strict;
use warnings;
use List::Util qw(min max);

sub tax_amount{
  my ($res,$prev) = (0,0);
  foreach(@{$_[1]}){
    $res += max(0,min($_[0],$_->[0]) - $prev) * $_->[1];
    $prev = $_->[0]
  }
  $res / 100.0
}

printf "%.2f\n",tax_amount(10,[[3,50],[7,10],[12,25]]);
printf "%.2f\n",tax_amount(2,[[1,0],[4,25],[5,50]]);
printf "%.2f\n",tax_amount(0,[[2,50]]);