package Day2::Part1;

use 5.36.0;

use List::Util qw/ sum pairmap /;
use List::MoreUtils qw/ part zip /;

sub read_file(@lines) {
    return map { [split] } @lines;
}

sub is_safe(@report) {
    my $asc = $report[1] - $report[0];

    my $level = shift @report;

    while(@report) {
        my $next = shift @report;
        my $delta = $next - $level;
        return 0 unless $delta*$asc >= 0;
        return 0 unless 1 <= abs($delta) <= 3;
        $level = $next;
    }

    return 1;
}

sub solve(@reports) {
    return sum map { is_safe(@$_) } @reports;
}

1;