拆分數組，隨機洗牌

Question

有沒有人知道我可以如何將一個數組拆分成兩個組，而沒有任何組（團隊在這種情況下）再次會見對方，直到耗盡可能性？

陣列[0，1，2，3，4，5]

Answer 1

這絕對不是要做到這一點的最佳方式，請你自己優化它（這將僅偶數隊的工作）：

<?php 
    $allTeams = [0,1,2,3,4,5]; 
    $everyGames = [];//Append team matches to this 
    foreach($allTeams as $team1){ 
     foreach($allTeams as $team2){ 
      if (!in_array([$team2, $team1], $everyGames) 
       && $team2 !== $team1) { 
       $everyGames[] = [$team1, $team2]; 
      }    

     } 
    } 
    $copyOfEveryGames = $everyGames; 
    $needToLoopAgain = true; 
    while($needToLoopAgain){ 
     $allRounds = []; 
     $needToLoopAgain = false; 
     $everyGames = $copyOfEveryGames; 
     shuffle($everyGames);//Shuffle it for the random array 
     while(count($everyGames) > 0){ 
      $allMatches = []; 
      $tempEveryGames = $everyGames; 
      for($i = 0; $i < count($allTeams)/2; $i++){ 
       foreach($tempEveryGames as $key => $game){ 
        if(!(in_array_r($game[0], $allMatches) || in_array_r($game[1], $allMatches))){ 
         $allMatches[] = $game; 
         unset($tempEveryGames[$key]); 
         break; 
        } 
       } 
      } 
      if(count($allMatches) === count($allTeams)/2){ 
       $everyGames = $tempEveryGames ; 

       $allRounds[] = $allMatches; 
      }else{ 
       $needToLoopAgain = true; 
       break; 
      } 
     } 
     if(count($allRounds) !== count($allTeams) -1){ 
      $needToLoopAgain = true; 
     } 
    } 

    //Display Example 
    foreach($allRounds as $round){ 
     print_r($round); 
     echo "<br>"; 
    } 
    /* 
    Example Output: 
    Array ([0] => Array ([0] => 0 [1] => 3) 
      [1] => Array ([0] => 1 [1] => 4) 
      [2] => Array ([0] => 2 [1] => 5)) 
    Array ([0] => Array ([0] => 0 [1] => 2) 
      [1] => Array ([0] => 4 [1] => 5) 
      [2] => Array ([0] => 1 [1] => 3)) 
    Array ([0] => Array ([0] => 1 [1] => 2) 
      [1] => Array ([0] => 3 [1] => 4) 
      [2] => Array ([0] => 0 [1] => 5)) 
    Array ([0] => Array ([0] => 1 [1] => 5) 
      [1] => Array ([0] => 0 [1] => 4) 
      [2] => Array ([0] => 2 [1] => 3)) 
    Array ([0] => Array ([0] => 0 [1] => 1) 
      [1] => Array ([0] => 2 [1] => 4) 
      [2] => Array ([0] => 3 [1] => 5)) 
    */ 

    //Copied from http://stackoverflow.com/questions/4128323/in-array-and-multidimensional-array 
    function in_array_r($needle, $haystack, $strict = false) { 
     foreach ($haystack as $item) { 
      if (($strict ? $item === $needle : $item == $needle) || (is_array($item) && in_array_r($needle, $item, $strict))) { 
       return true; 
      } 
     } 

     return false; 
    } 

?> 

Answer 2

我希望這會回答你的問題，如果我很好地理解你的問題。

function againstWho(array $teams) : array{ 
    $fixture = null; 

    foreach($teams as $key => $team){ 

     unset($teams[$key]); 
     $fixture[$team] = $teams; 
     $teams[] = $team; 

    } 

    return $fixture; 
} 

// EXAMPLE 

$teams = ['MANU', 'ARS', 'LIV', 'CHE', 'MANC']; 

foreach (againstWho($teams) as $team => $fixtures){ 

    echo "$team will face "; 
    foreach ($fixtures as $key => $rival){ 
     echo "$rival, "; 
    } 
    echo "<br />"; 
} 

// Her's what gets printed 
/* 

MANU will face ARS, LIV, CHE, MANC, 
ARS will face LIV, CHE, MANC, MANU, 
LIV will face CHE, MANC, MANU, ARS, 
CHE will face MANC, MANU, ARS, LIV, 
MANC will face MANU, ARS, LIV, CHE 

*/