#!/usr/bin/perl -w

use strict;

my $arr = ['A -4 C','C -4 B','B -4 A','A -2 C','C -3 B'];


my @a = do {
    my $idx = 0;
    map {
        {
            data => [ split ' ', $_ ],
            idx  => $idx++,
        }
    }@$arr
};

use Data::Dumper;
print Dumper(\@a);