sub twosum_NetWallah{
  my ($inp, $target)=@_;
  my %targ_idx = map { $inp->[$_] => $_ } 0..$#$inp;

  for (0..$#$inp){
     next unless defined ( my $other=$targ_idx{ $target - $inp->[$_] } );
     next if $other == $_;
     return [ $other > $_ ? ($_, $other) : ($other, $_) ];
  }
  return undef;
}	

# Test NetWallah..
for my $test (@tests) {
    is_deeply
        sort_arrayref(twosum_NetWallah ($test->[INPUT], $test->[TARGET])),
        sort_arrayref($test->[EXPECTED]);
}

##</code><code>##

    [[-5,-3,1,4,7], 1, [1,3]],