生成並保存百萬個唯一代碼

Question

我正在使用Laravel 5.1框架。

我需要從字符'BCDFGHIJKLMNPQRSTVWXYZ'取5，例如DFGHJ創建一組唯一代碼。

所以，我的代碼是這樣的：

$maxCodes = 1200000; 
$codeSize = 5; 
$characters = 'BCDFGHJKLMNPQRSTVWXY'; 
$cLenght = strlen($characters); 
$sizeBlock = $maxCodes/($cLenght*4); // For not overflow memory when put the codes in array 

for ($i=0; $i < $cLenght; $i++) { 
    $subCharacters = str_replace($characters[$i], '', $characters); 
    $existCodes = []; 
    for ($k = 0; $k < 4; $k++) { 
     $codesToInsert = []; 
     for ($j = 0; $j < $sizeBlock;) { 
      $code = $characters[$i] . substr(str_shuffle($characters), 0, $codeSize-1); 

      if (!isset($existCodes[$code])) { 
       $existCodes[$code] = ''; 
       array_push($codesToInsert, ['code' => $code, 'used' => 0, 'rand' => rand(0,10)]); 
       $j++; 
      } 
     } 

     \App\Code::insert($codesToInsert); 
    } 
} 

我會解釋一下我的代碼。因爲我的代碼是按字母順序排列的，所以我把一個隨機數的字段rand（我創建這個字段用於下一個查詢，如Code :: where（'used'，0） - > where（'rand'，rand（0 ，9）），通過這種方式我檢索了一個隨機代碼，而不是按字母順序）

問題是當我運行函數來生成代碼，其創建只有135000不是$ maxCodes，但我不知道爲什麼？ ..

有人可以幫助我嗎？

謝謝！

PS.-對不起給我English ..

Answer 1

代碼已被評論。

限制：越接近組合的限制，那麼'重複生成的計數'將變得愚蠢。我希望在我的電腦上生成所有120萬個代碼大約需要30分鐘。我預計它會花費150萬美元。很有意思。

詳細的字母 'B' 的樣品包括重複計算

$tryCount integer89166 
$existCount integer68422 

Timings: 

Script start date and time : 2015-12-09 15:45:47.172 
Script stop end date and time: 2015-12-09 15:46:40.109 
Total execution time : 52.938000000000002 

樣品：

'BXCLF' => integer 6 
'BYRXS' => integer 6 
'BPGGG' => integer 6 
'BRQJJ' => integer 6 
'BKJKQ' => integer 6 
'BNQVG' => integer 6 
'BLQSX' => integer 6 
'BCGDH' => integer 5 
'BBLFG' => integer 5 
'BFBJQ' => integer 5 
'BRVRJ' => integer 5 
'BJXTX' => integer 5 

硬件：電腦 - 雙倉鼠供電。

爲RandomData類的代碼：Random data for use in PHP

代碼：

<?php 

include __DIR__ . '/__bootstrap__.php'; 

use app\system\encryption\RandomData; 
use app\system\ElapsedTiming; 

$maxCodes = 50000; 
$codeSize = 5; 
$characters = 'BCDFGHJKLMNPQRSTVWXY'; 
$cLength = strlen($characters) - 1; 

$codesPerLetter = (int) $maxCodes/$cLength; // how many to generate for this initial letter 

$timer = new ElapsedTiming(); 
$timer->start(); 

/** 
* @var RandomData 
*/ 
$randSrc = RandomData::instance(); // source of random numbers 

for ($i=0; $i < $cLength; $i++) { // use each char as an initial character 

    $existCodes = array(); // current batch of codes in here 
    $existCount = 0; 

    $newCode = $characters[$i] . '0000'; // each `batch` starts with a different letter 
             // then four random letters from the string... 

    $tryCount = 0; // count the number of attemps to generate the required count 
    while ($existCount < $codesPerLetter) { 

     // generate a random 4 character string using all the characters 
     for ($k = 1; $k < 5 ; $k++) { // first lether is fixed then fill in the rest 
      // generate code... 
      $char = $characters[$randSrc->int32(0, $cLength)]; 
      $newCode[$k] = $char; 
     } 

     $tryCount++; 

     // test if exists 
     if (isset($existCodes[$newCode])) { // store as keys not values 
      $existCodes[$newCode]++;   // count duplicate generation 
     } 
     else { 
      $existCodes[$newCode] = 1;  // a new one 
      $existCount++;     // closer to the target 
     } 
    } 

    /** 
    * Write this batch of codes to the array to the database... 
    */ 
} 

/* debug information */ 
$timer->stop(); 
arsort($existCodes); 

$timer->printFullStats(); 

\Kint::dump($tryCount, $existCount, array_slice($existCodes, 0, 100));