use strict;
use warnings;

open(my $N148,'<',"148Nsorted.bed") or die $!;

open(my $N162,'<',"162Nsorted.bed") or die $!;

open(my $N174,'<',"174Nsorted.bed") or die $!;

open(my $N175,'<',"175Nsorted.bed") or die $!;

my ($chr148, $start148, $end148) = scan($N148);
my ($chr162, $start162, $end162) = scan($N162);
my ($chr174, $start174, $end174) = scan($N174);
my ($chr175, $start175, $end175) = scan($N175);

my ($minstart, $maxstart, $minend, $maxend);

while(defined($chr148)) {
    $minstart = $start148;
    $maxstart = $start148;
    $minend = $end148;
    $maxend = $end148;
    while(defined($chr162) and $chr162 lt $chr148) {
        ($chr162, $start162, $end162) = scan($N162);
    }
    while(defined($chr162) and $chr162 eq $chr148) {
        $minstart = $start162 if($start162 < $minstart);
        $maxstart = $start162 if($start162 > $maxstart);
        $minend = $end162 if($end162 < $minend);
        $maxend = $end162 if($end162 > $maxend);
        if($maxstart <= $minend) {
            while(defined($chr174) and $chr174 lt $chr148) {
                ($chr174, $start174, $end174) = scan($N174);
            }
            while(defined($chr174) and $chr174 eq $chr148) {
                $minstart = $start174 if($start174 < $minstart);
                $maxstart = $start174 if($start174 > $maxstart);
                $minend = $end174 if($end174 < $minend);
                $maxend = $end174 if($end174 > $maxend);
                if($maxstart <= $minend) {
                    while(defined($chr175) and $chr175 lt $chr148) {
                        ($chr175, $start175, $end175) = scan($N175);
                    }
                    while(defined($chr175) and $chr175 eq $chr148) {
                        $minstart = $start175 if($start175 < $minstart);
                        $maxstart = $start175 if($start175 > $maxstart);
                        $minend = $end175 if($end175 < $minend);
                        $maxend = $end175 if($end175 > $maxend);
                        if($maxstart <= $minend) {
                            print "$chr148 $minstart $maxend\n";
                        }
                        ($chr175, $start175, $end175) = scan($N175);
                    }
                }
                ($chr174, $start174, $end174) = scan($N174);
            }
        }
        ($chr162, $start162, $end162) = scan($N162);
    }
    ($chr148, $start148, $end148) = scan($N148);
}



close($N148);
close($N162);
close($N174);
close($N175);

exit(0);


sub scan {
    my ($fh) = @_;

    my $line = <$fh>;
    return() unless($line);
    return(split(/\t/, $line));
}

##</code><code>##

use strict;
use warnings;
use List::Util qw(min max);

my $ranges148 = scan('148Nsorted.bed');
my $ranges162 = scan('162Nsorted.bed');
my $ranges174 = scan('174Nsorted.bed');
my $ranges175 = scan('175Nsorted.bed');


foreach my $chr (keys %$ranges148) {
    foreach my $range148 (@{$ranges148->{$chr}}) {
        foreach my $range162 (@{$ranges162->{$chr}}) {
            foreach my $range174 (@{$ranges174->{$chr}}) {
                foreach my $range175 (@{$ranges175->{$chr}}) {
                    my $minstart = min(
                        $range148->[0],
                        $range162->[0],
                        $range174->[0],
                        $range175->[0]);
                    my $maxstart = max(
                        $range148->[0],
                        $range162->[0],
                        $range174->[0],
                        $range175->[0]);
                    my $minend = min(
                        $range148->[1],
                        $range162->[1],
                        $range174->[1],
                        $range175->[1]);
                    my $maxend = max(
                        $range148->[1],
                        $range162->[1],
                        $range174->[1],
                        $range175->[1]);

                    if($maxstart <= $minend) {
                        print "overlapping $chr: $minstart, $maxend - ($range148->[0], $range148->[1]), ($range162->[0], $range162->[1]), ($range174->[0], $range174->[1]), ($range175->[0], $range175->[1])\n";
                    } else {
                        print "not overlapping: $chr: $minstart, $maxend - ($range148->[0], $range148->[1]), ($range162->[0], $range162->[1]), ($range174->[0], $range174->[1]), ($range175->[0], $range175->[1])\n";
                    }
                }
            }
        }
    }
}

exit(0);


sub scan {
    my ($file) = @_;

    open(my $fh, '<', $file) or die "$file: $!";

    my $ranges;
    foreach my $line (<$fh>) {
        chomp($line);
        my ($chr, $start, $end) = split(/\t/, $line);
        push(@{$ranges->{$chr}}, [ 0+$start, 0+$end ]);
    }
    return($ranges);
}