Array Permutation

[jeeva]

Dear friends,

 

I am having problems as I would like to take values out of an array

 

Example

$name = array (a,b,c);

 

and the output should be like

 

eg

a,b,c

a,b

a,c

b,c

 

Does anyone know how to do this?

 

Thanks

Jeeva

[sasa]

try

<?php
$a = array(1,2,3,4);
function my_permut($a){
if (count($a) == 1)return array($a, array());
$out = array();
foreach ($a as $k => $v){
	unset($a[$k]);
	$b = my_permut($a);
	$out = array_merge(my_merge($v, $b), $out);
	$out = array_merge($out, $b);
	break;
}
return $out;
}
function my_merge($a, $b){
if (count($b) == 0) return array($a);
foreach ($b as $k => $v){
	array_unshift($v, $a);
	$b[$k] = $v;
}
return $b;
}
$b = my_permut($a);
print_r($b);
?>

[jeeva]

thanks sasa

 

But can't we make this without loop...?

because it takes lot of time when i give more than 10 values.

 

 

Thanks

Jeeva

[GingerRobot]

What are you trying to do? List all possible combinations?

 

Of course this is going to take a long time. There are n^n possibilities. The number of possibilities is going to grow pretty rapidly as n increases.

 

However sasa' code does not return all possible values. For example, proding two numbers, 1 and 2, it would not return 2,1 as a combination. The code provided appears to run relatively quickly for 12 numbers here.

[jeeva]

thanks GingerRobot

 

sasa code is  right for me. that is wt i expected actually ..

here 1,2 is equal to 2,1

 

By using this i want to search candidate profile..

for example,

 

if user will give keyword like a,b,c

i want to search all possibilities like

1. a and b and c

2. a and b

3. b and c

4. a and c

and a,b,c

 

 

Thanks

Jeeva

[sasa]

number of subsets of set with n elements is 2^n (include empty set)

no way to be less

[dooper3]

They are right Jeeva, but I don't see the problem, surely you'll never have 10 values for n anyway, because very few people enter more than 3-5 words when performing a search, so there shouldn't be too much trouble...

[jeeva]

Thank u very much chums.......