Permutation of Array PHP

问题

I have the following problem:

$multidmimensional = array(

 [0] => array(
    [0] => 1, 
    [1] => 2, 
    [2] => 3
  );


  [1] => array(
   [0] => 5, 
   [1] => 6, 
   [2] => 7
  );

  ...

  [2] => array(
   [0] =>,4 
   [1] => 5, 
  );

);

I can have one or more (nested) arrays, and lets take as an example the first two of the above arrays:

I should permutate them in the following way:

If I had for example those three arrays, I should get a result like this:

I am having some problems to make an algorithm that would fix this problem. Can anyone help me? Thanks in advance.

回答1:

That's a nice brain teasing question. Here's what I came up with, see the running demo for testing and adjusting.

$multidimensional = array(
  0 => array(
    0 => 1,
    1 => 2,
    2 => 3,
  ),
  1 => array(
    0 => 5,
    1 => 6,
    2 => 7,
  ),
  2 => array(
    0 => 4,
    1 => 5,
  ),
); // just your input


$permutations = array();
$count = count($multidimensional);
for ($i = 0; $i < $count; $i++) {
  $temp = array_map("permute",array($permutations),array($multidimensional[$i]));
  $permutations = $temp[0];
}
print_r($permutations); // OUTPUT

function permute($base,$add) {
  $result = array();
  if (count($base) > 0) {
    foreach ($base AS $val1) {
      if (count($add) > 0) {
        foreach ($add AS $val2) {
          $result[] = $val1.$val2;
        }
      }
      else {
        $result = $base;
      }
    }
  }
  else {
    $result = $add;
  }
  return $result;
}

回答2:

I can not test it right now but this should work: (may contain typos)

function permute($arrays){
      if(count($arrays)<2) return $arrays[0];//TODO error on count == 0
      $array1 = array_shift($arrays);
      $array2 = array_shift($arrays);
      $results = array();
      foreach($array1 as $elementOfOne){
        foreach($array2 as $elementOfTwo){
          $results[] = $elemnetOfOne . $elementOfTwo;
        }
      }
      array_unshift($arrays, $results);
      return permute($arrays);
    }

回答3:

$data = array
(
  '1' => array(5, 6, 7),
  '2' => array(9, 25, 14)

);

for($i=0; $i<=count(array_keys($data)); $i++) {
   for($j=1; $j<=2; $j++) {
      $values[$i][] = $data[$j][$i];
   }
}

for($i=0; $i<count($values); $i++) {
  shuffle($values[$i]);
}

$newData = array();
for($i=0; $i<3; $i++) {
   for($j=1; $j<=2; $j++) {
       $newData[$j][] = array_pop($values[$i]);
   }
}
print_r($newData);

Fiddle

来源：https://stackoverflow.com/questions/10734514/permutation-of-array-php

标签

php

arrays

loops

for-loop

permutation