Original Array:   14  11  10  13  11
       New Positions:    4   1   0   3   2

       Ordered Array:   10  11  11  13  14
  Original Positions:    2   1   4   3   0

##</code><code>##

#!/usr/bin/env perl

## script to practice creating numeric orderings

use strict ;
use warnings ;

## we want to find the POSITION of each value after ordering
my @values = ( 14 , 11 , 10 , 13 , 11 ) ; 

## now let's do some ordering!
my %orderings = order( @values ) ;

## 
## print original array and positions after ordering

print "\n      Original Array: " ; 
foreach my $value ( @values ) {
    print sprintf( "% 4d" , $value ) ; 
}

print "\n       New Positions: " ; 
foreach my $ordering ( @{ $orderings{ "new_pos" } } ) {
    print sprintf( "% 4d" , $ordering ) ; 
}
print "\n" ; 

## 
## print ordered array and original positions 

print "\n       Ordered Array: " ; 
foreach my $ordering ( @{ $orderings{ "orig_pos" } } ) {
    print sprintf( "% 4d" , $values[ $ordering ] ) ; 
}

print "\n  Original Positions: " ; 
foreach my $ordering ( @{ $orderings{ "orig_pos" } } ) {
    print sprintf( "% 4d" , $ordering ) ; 
}
print "\n\n" ; 


##  ##  ##  ##  ##  ##  ##  ##  ##  ##  ##  ##  ##  ##  ##  ##  
  ##  ##  ##  ##  ##  ##  ##  ##  ##  ##  ##  ##  ##  ##  ##  
##  ##  ##  ##  ##  ##  ##  ##  ##  ##  ##  ##  ##  ##  ##  ##  

sub order {
    my @inarray = @_ ; 

    ## elements of @inarray MUST be numeric
    foreach my $inval (@inarray) {
	if ( ! is_float( $inval ) ) {
	    die "Fatal error. All elements of the \"order\" subroutine must be numeric." ; 
	}
    }
    my @sorted = sort { $a <=> $b } @inarray ;

    ## make backups 
    my @inarray_bkp = @inarray ; 
    my @sorted_bkp  = @sorted ; 

    ## now get original and new positions -- store in hash of arrays 
    my %orderings ; 

    ## get the original positions 
    for my $i (0..$#sorted) {
	for my $j (0..$#inarray) {

	    if ( $sorted[$i] eq $inarray[$j] ) {
		
		## return the original position
		push( @{ $orderings{ "orig_pos" } } , $j ) ;
		
		## disqualify as future candidates
		$sorted[$i]  = "AA" ; 
		$inarray[$j] = "ZZ" ; 
	    }
	}
    }

    ## restore from backups 
    @inarray = @inarray_bkp ; 
    @sorted  = @sorted_bkp ; 

    ## get the new positions 
    for my $i (0..$#inarray) {
	for my $j (0..$#sorted) {

	    if ( $inarray[$i] eq $sorted[$j] ) {
		
		## return the new position
		push( @{ $orderings{ "new_pos" } } , $j ) ;

		## disqualify as future candidates
		$inarray[$i] = "AA" ; 
		$sorted[$j]  = "ZZ" ; 
	    }
	}
    }

    ## return the original and new positions
    return %orderings ; 
}


sub is_float {
    my $inval = $_[0] ; 
    defined $inval && $inval =~ /^[+-]?\d+(\.\d+)?$/;
}