生成单词组合

Question

例如，这是我的文本：

$str = 'buy new microsoft windows';

我用数组​​分解文本和列表：

Array
(
    [0] => buy
    [1] => new
    [2] => microsoft
    [3] => windows
)

我想在数组中生成类似这样的单词：

buy new
buy new windows
buy microsoft 
buy microsoft windows
buy windows
new microsoft
new microsoft windows
new windows
microsoft windows

我尝试使用 foreach 和 rand 但无法生成如图所示的内容。有没有机会按照我的要求生成？

Answer 1

你可以看看这个 PEAR 包
用法示例：

<?php
require_once 'Math/Combinatorics.php';
$words = array('buy', 'new', 'microsoft');
$combinatorics = new Math_Combinatorics;
foreach($combinatorics->permutations($words, 2) as $p) {
  echo join(' ', $p), "\n"; 
}

输出将是：

buy new
new buy
buy microsoft
microsoft buy
new microsoft
microsoft new

Answer 2

shuffle($array);
echo join(' ', array_slice($array, 0, mt_rand(1, count($array))));

这会给你一个随机“句子”。根据需要重复。

Answer 3

从 php.net shuffle doc 找到

function powerSet($in,$minLength = 1) { 
   $count = count($in); 
   $members = pow(2,$count); 
   $return = array(); 
   for ($i = 0; $i < $members; $i++) { 
      $b = sprintf("%0".$count."b",$i); 
      $out = array(); 
      for ($j = 0; $j < $count; $j++) { 
         if ($b{$j} == '1') $out[] = $in[$j]; 
      }
      $out_val = implode(" ", $out); 
      if (count($out) >= $minLength) { 
         $return[] = $out_val; 
      } 
   } 
   return $return; 
}

print_r(powerSet($str_arr));

，结果将是，

Array
(
    [0] => windows
    [1] => microsoft
    [2] => microsoft windows
    [3] => new
    [4] => new windows
    [5] => new microsoft
    [6] => new microsoft windows
    [7] => buy
    [8] => buy windows
    [9] => buy microsoft
    [10] => buy microsoft windows
    [11] => buy new
    [12] => buy new windows
    [13] => buy new microsoft
    [14] => buy new microsoft windows
)

Answer 4

function pc_permute($items, $perms = array( )) {
    if (empty($items)) {
        print join(' ', $perms) . "\n";
    } else {
        for ($i = count($items) - 1; $i >= 0; --$i) {
            $newitems = $items;
            $newperms = $perms;
            list($foo) = array_splice($newitems, $i, 1);
            array_unshift($newperms, $foo);
            pc_permute($newitems, $newperms);
        }
    }
}

来源： http://docstore.mik .ua/orelly/webprog/pcook/ch04_26.htm#phpckbk-CHP-4-EX-6

还检查​​该站点

---

示例上的下一个示例： pc_permute(explode('','购买新的微软Windows'));

buy new microsoft windows
new buy microsoft windows
buy microsoft new windows
microsoft buy new windows
new microsoft buy windows
microsoft new buy windows
buy new windows microsoft
new buy windows microsoft
buy windows new microsoft
windows buy new microsoft
new windows buy microsoft
windows new buy microsoft
buy microsoft windows new
microsoft buy windows new
buy windows microsoft new
windows buy microsoft new
microsoft windows buy new
windows microsoft buy new
new microsoft windows buy
microsoft new windows buy
new windows microsoft buy
windows new microsoft buy
microsoft windows new buy
windows microsoft new buy

Answer 5

对于所有可能的组合，我改进了 @SujitAgarwal 答案：

下载 Math_Combinatoeics 。

include_once 'Combinatorics.php';

$words = array('buy','microsoft','windows');
$count = count($words);
$return = array();

$combinatorics = new Math_Combinatorics;

for ($num=1; $num <= $count; $num++ ){
  foreach($combinatorics->permutations($words, $num) as $p) {
    $return[] = join(' ', $p);
  }
} 

print_r($return);

输出 ：

Array
(
  [0] => buy
  [1] => microsoft
  [2] => windows
  [3] => buy microsoft
  [4] => microsoft buy
  [5] => buy windows
  [6] => windows buy
  [7] => microsoft windows
  [8] => windows microsoft
  [9] => buy microsoft windows
  [10] => buy windows microsoft
  [11] => microsoft windows buy
  [12] => microsoft buy windows
  [13] => windows buy microsoft
  [14] => windows microsoft buy
)