asked on

Sortting an array

I have a list of names like this.

[0]Bob
[1]Joe
[2]Bob
[3]Bob
[4]Bob
[5]Joe
[6]Phil
[7]Phil

I want to sort my array without changing it so that its like this (so basically give an alternative index of elements so its like this):

[0]Bob
[2]Bob
[3]Bob
[4]Bob
[1]Joe
[5]Joe
[6]Phil
[7]Phil

#Class contains the name information.
 
$m=0;
$no=0;
$kl =0;
@keep=();
 
foreach (@Class){
	$test = $no;
		foreach $u (0..$#keep){
			if ($_=~m/$keep[$u]/){
				$no++;
			} elsif ($_ =~ m/^[ \t]*$/){
				$Class[$m]="CHECK MANUALLY";
			}
		}
		if ($no==$test){
		$keep[$kl] = $_;
		$kl++;
		}
	$m++;
}
 
@keep2=();
@index =();
$indcount=0;
foreach $hu (@keep){
 
	foreach $ij (0..$#Class){
		if ($Class[$ij] =~ m/$hu/){
			$index[$indcount]=$ij;
			$indcount++;
		}
	}
	
}

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kawas

To sort an array in ASCII (Alphabetical) order :
sort(@array);

Example of storing a sort result back into the same array :
@array = sort (@array);

To sort an array in reverse ASCII (Alphabetical) order :
sort {$b cmp $a} (@array);

To sort an array in numeric ascending order :
sort {$a <=> $b} (@array);

To sort an array in numeric decending order :
sort {$b <=> $a} (@array);

To print a sorted array but not alter the original :
print sort(@array);

To reverse the value elements in an array :
reverse (@array);

from http://www.htmlite.com/perl016.php

sanjangeorge

ASKER

Yeah i've seen things like this not quite what im looking for

kawas

if you are trying to sort the arrays and keep indices (old and new) maybe the data structure you are using isnt correct for you.

Todd Mummert

#!/usr/bin/perl -w
use strict;
 
my @unsorted = (
             "[0]Bob",
             "[1]Joe",
             "[2]Bob",
             "[3]Bob",
             "[4]Bob",
             "[5]Joe",
             "[6]Phil",
             "[7]Phil"
             );
 
my @sorted = sort {
   $a =~ /^\[(\d+)\](.*)$/ or die "input $a not in expected form\n";
   my ($a1, $a2) = ($1, $2);
   $b =~ /^\[(\d+)\](.*)$/ or die "input $b not in expected form\n";
   my ($b1, $b2) = ($1, $2);
   $a2 eq $b2 ? $a1 <=> $b1 : $a2 cmp $b2;
} @unsorted;
 
print join("\n", @sorted)."\n";

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ASKER CERTIFIED SOLUTION

Adam314

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ozo

my @unsorted = (
"[0]Bob",
"[1]Joe",
"[2]Bob",
"[3]Bob",
"[4]Bob",
"[5]Joe",
"[6]Phil",
"[7]Phil"
);
$\=$/;
print for @sorted = map{/\0(.*)/}sort map{join"\0",(/([][\d]*(.*))/)[1,0]} @unsorted ;