sub bin_search {
  
  my ($array, $word) = @_;
  my ($low, $high) = ( 0, @$array - 1 );

 while ( $low <= $high ) { # While the window is open

   my $try = int( ($low+$high) /2 ); # Try the middle element

   $low = $try+1, next if $array->[$try] lt $word; # Raise bottom
   $high = $try-1, next if $array->[$try] gt $word; # Lower top

    return $try; # We've found the word!

  }

 return;

}
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