Why not use a for loop like so:

use warnings;
use strict;

  my @alpha = qw(a b c d e f);

  my @location = qw(0 2 4);

   print $alpha[$_+1] for @location; # prints bdf
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Update:
NOTE: Another thought, can the array with location be larger than the array that contains words to find?
If so, then the solution adds just a simple if statement.

  my @alpha = qw(a b c d e f);

  my @location = qw(0 2 4 6 8 10 12);

  for (@location){
     print $alpha[$_+1] if defined $alpha[$_+1];
  }
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