#!/usr/bin/perl
#       fuzzy-size.pl
#       =  Copyright 2010 Xiong Changnian <xiong@sf-id.com>  =
#       = Free Software = Artistic License 2.0 = NO WARRANTY =

use strict;
use warnings;
use feature qw( say );

# "How many apples are in the box?" 
# This is an ordinary question asked by ordinary people every day. 
# It's not the same as "Count the apples in the box." 
# A rough estimate will be fine. 
# 
# fuzz() returns 0 for 0 and the exact number for 1, 2, or 3. 
# It returns 3 ("a few") for 4 also and 6 ("half dozen") for 5..7;
#   and so forth for increasing magnitudes. 
# fuzz() returns "the same" (negated) values for negative integers;
#   we sometimes ask "How many do we need" as well. 
# But fractions are ignored; you don't count broken apples. 

#
my @raw = (
-768,
-9,
-3,
-2,
-1,
-0.5,
0,
0.005,
0.5,
1,
2,
3,
4,
5,
6,
7,
8,
9,
10,
11,
12,
13,
14,
15,
16,
17,
18,
19,
20,
21,
23,
100,
768,
18433,
633999,
);

my $in          ;
my $out         ;

foreach $in ( @raw ) {
    $out        = fuzz( $in );
    say $in, qq{\t}, $out;
};

sub fuzz {
    my $in          = int shift;                # no floats here, move
+ along
    my $out         ;
    
    return 0 if ( $in == 0 );
    
    my $negative    = ( $in < 0 );              # store algebraic sign
    $in             = abs $in;
    
    $out            = int sqrt exp ( (int log $in**2) + 0.7 );
    
    if ( $negative ) { $out = 0 - $out; };      # restore sign
    
    return $out;
};

__DATA__

Output: 

-768    -943
-9      -10
-3      -3
-2      -2
-1      -1
-0.5    0
0       0
0.005   0
0.5     0
1       1
2       2
3       3
4       3
5       6
6       6
7       6
8       10
9       10
10      10
11      10
12      10
13      17
14      17
15      17
16      17
17      17
18      17
19      17
20      17
21      28
23      28
100     127
768     943
18433   18958
633999  627814

__END__
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