use strict; 
use warnings; 
my @a = ( 2,   5,   4,   3); 
my @b = ('a', 'b', 'c', 'd'); 
my @temp = map {[$a[$_],$b[$_]]} 0..$#a; 
@temp = sort {$a->[0] <=> $b->[0]} @temp; 
@a = map {$_->[0]} @temp; 
@b = map {$_->[1]} @temp; 
print @a, "\n"; 
print @b, "\n";