Parsing line and selecting values corresponding to a key

Question

there is a set of data which is arranged in a specific manner (as a tree), as is given below. basically a key=value pair, with some additional values at the end, which informs how many children does the branch have and some junk value.

11=1 123 2
11=1>1=45 234 1
11=1>1=45>9=16 345 1
11=1>1=45>9=16>2=34 222 1
11=1>1=45>9=16>2=34>7=0 2234 1
11=1>1=45>9=16>2=34>7=0>8=0 22345 1
11=1>1=45>9=16>2=34>7=0>8=0>0=138 22234 1
11=1>1=45>9=16>2=34>7=0>8=0>0=138>5=0 5566 1
11=1>1=45>9=16>2=34>7=0>8=0>0=138>5=0>4=0 664 1
11=1>1=45>9=16>2=34>7=0>8=0>0=138>5=0>4=0>6=10 443 1
11=1>1=45>9=16>2=34>7=0>8=0>0=138>5=0>4=0>6=10>3=11 445 0
11=1>1=47 4453 1
11=1>1=47>9=16 887 1
11=1>1=47>9=16>2=34 67 1
11=1>1=47>9=16>2=340>7=0 98 1
11=1>1=47>9=16>2=34>7=0>8=0 654 1
11=1>1=47>9=16>2=34>7=0>8=0>0=138 5789 1
11=1>1=47>9=16>2=34>7=0>8=0>0=138>5=0 9870 1
11=1>1=47>9=16>2=34>7=0>8=0>0=138>5=0>4=0 3216 1
11=1>1=47>9=16>2=34>7=0>8=0>0=138>5=0>4=0>6=10>3=11 66678 0

my problem is to get the appropriate branch from the above data, which satisfies exactly the values, which i give as the input. suppose, my input value to search in the above data stack are:

5=0
4=0
6=10
3=11
11=1
1=45
0=138
9=16
2=34
7=0
8=0

for the above given list of key->values, the function should return 11=1>1=45>9=16>2=34>7=0>8=0>0=138>5=0>4=0>6=10>3=11 as the match. likewise, for another input file, in which another set of keys is given:

5=0
4=0
6=10
3=11
11=1
1=45
9=16
2=34
7=0
8=0

the function should return 11=1>1=45>9=16>2=34>7=0>8=0 1 as the match. not the last line; as that would also match all the values given in my input key, but, i want only the exact match.

Also, I want to find out how many nodes were selected in the given array. (separated by >).

What will be the best way to implement this kind of scenario?

Answer 1

use strict;
use warnings;

my $tree;
while (<DATA>) {
    my @data = split /\>/, (/^([^ ]*)/)[0];
    my $ptr = \$tree;
    for my $key (@data) {
        $ptr = \$$ptr->{$key};
    }
}

my @inputs = (
    [qw(5=0 4=0 6=10 3=11 11=1 1=45 0=138 9=16 2=34 7=0 8=0)],
    [qw(5=0 4=0 6=10 3=11 11=1 1=45 9=16 2=34 7=0 8=0)]
);

sub getKey {
    my ( $lu, $node ) = @_;
    exists $lu->{$_} and return $_ for keys %$node;
}

for my $input (@inputs) {
    my %lu;
    @lu{@$input} = ();
    my @result;
    my $node = $tree;
    while (%lu) {
        my $key = getKey( \%lu, $node );
        if ($key) {
            $node = $node->{$key};
            push @result, $key;
            delete $lu{$key};
        }
        else {
            last;
        }
    }
    print join( '>', @result ), "\n";
}

__DATA__
11=1 123 2
11=1>1=45 234 1
11=1>1=45>9=16 345 1
11=1>1=45>9=16>2=34 222 1
11=1>1=45>9=16>2=34>7=0 2234 1
11=1>1=45>9=16>2=34>7=0>8=0 22345 1
11=1>1=45>9=16>2=34>7=0>8=0>0=138 22234 1
11=1>1=45>9=16>2=34>7=0>8=0>0=138>5=0 5566 1
11=1>1=45>9=16>2=34>7=0>8=0>0=138>5=0>4=0 664 1
11=1>1=45>9=16>2=34>7=0>8=0>0=138>5=0>4=0>6=10 443 1
11=1>1=45>9=16>2=34>7=0>8=0>0=138>5=0>4=0>6=10>3=11 445 0
11=1>1=47 4453 1
11=1>1=47>9=16 887 1
11=1>1=47>9=16>2=34 67 1
11=1>1=47>9=16>2=340>7=0 98 1
11=1>1=47>9=16>2=34>7=0>8=0 654 1
11=1>1=47>9=16>2=34>7=0>8=0>0=138 5789 1
11=1>1=47>9=16>2=34>7=0>8=0>0=138>5=0 9870 1
11=1>1=47>9=16>2=34>7=0>8=0>0=138>5=0>4=0 3216 1
11=1>1=47>9=16>2=34>7=0>8=0>0=138>5=0>4=0>6=10>3=11 66678 0