Re: min and mindex

[Kenosis]

Given your one-to-one mapping between the two arrays (i.e., the same number of elements) and the numbers in @array1 are not repeated, consider the following:

use strict;
use warnings;
use List::Util 'min';

my %hash;
my @array1 = ( 5,   2,   3,   4,   1,   6,   7 );
my @array2 = ( "a", "b", "c", "d", "e", "f", "g" );

my %array1Hash = map { $array1[$_] => $_ } 0 .. $#array1;

@hash{@array1} = @array2;

my $array1Min = min @array1;

print 'The minimum value in @array1 is ', $array1Min, ".\n";

print 'The position of ', $array1Min, ' in @array1 is ',
  $array1Hash{$array1Min}, ".\n";

print 'The element in @array2 at position ', $array1Min, ' is ',
  $hash{ min @array1 }, '.';

Output:

The minimum value in @array1 is 1.
The position of 1 in @array1 is 4.
The element in @array2 at position 1 is e.

Two hashes are created. The first (%array1Hash) pairs each element of @array1 with its position in the array. The second (%hash) pairs the elements of @array1 as the keys with the elements of @array2 as values. When you've found the minimum value in @array1, you can use it as the key to get the associated value from @array2.

Hope this helps!

Update: Added printing the min val of @array1 and that element's position in the array.

[Anonymous Monk]

I like this example. What would you do if the values in array1 were not unique?

[Kenosis]

Perhaps something like the following:

use strict;
use warnings;
use List::Util 'min';

my %array1Hash;
my @array1 = ( 5,   2,   1,   4,   1,   6,   7 );
my @array2 = ( "a", "b", "c", "d", "e", "f", "g" );

push @{ $array1Hash{ $array1[$_] } }, $_ for 0 .. $#array1;
my %array2Hash = map { $_ => $array2[$_] } 0 .. $#array2;

my $array1Min = min @array1;
my $positions = join ', ', @{ $array1Hash{$array1Min} };
my $elements  = join ', ', map $array2Hash{$_}, @{ $array1Hash{$array1
+Min} };

print 'The minimum value in @array1 is ', "$array1Min.\n";

print 'The position(s) of ', $array1Min, ' in @array1: ', "$positions.
+\n";

print 'The element(s) in @array2 at position(s) ', "$positions: $eleme
+nts.";

Output:

The minimum value in @array1 is 1.
The position(s) of 1 in @array1: 2, 4.
The element(s) in @array2 at position(s) 2, 4: c, e.