在 PHP 中使用条件语句进行二维关联数组排序

Question

我无法弄清楚如何解决这个问题，它来自一个免费的在线测试网站。这是链接：https://www.testdome.com/questions/php/league-table/19939?questionIds=7278,19939&generatorId=30&type=fromtest&testDifficulty=Hard

但为了更清楚，我也在写这个问题和我的答案。开始的答案在上面写的链接中。

问题：

LeagueTable 类跟踪联盟中每个玩家的得分。每场比赛结束后，玩家使用 recordResult 函数记录他们的得分。

玩家在联赛中的排名使用以下逻辑计算：

得分最高的玩家排名第一（排名 1）。得分最低的玩家排名最后。 如果两名球员得分相同，则比赛次数最少的球员排名较高。 如果两名球员的得分和比赛次数并列，那么在球员名单中排名第一的球员排名更高。 实现 playerRank 函数，返回给定排名的玩家。

例如：

$table = new LeagueTable(array('Mike', 'Chris', 'Arnold'));
$table->recordResult('Mike', 2);
$table->recordResult('Mike', 3);
$table->recordResult('Arnold', 5);
$table->recordResult('Chris', 5);
echo $table->playerRank(1);

所有玩家的得分相同。不过，阿诺德和克里斯的比赛场次都比迈克少，而且由于克里斯在球员名单中排在阿诺德之前，所以他排名第一。因此，上面的代码应该显示“Chris”。

我的代码：

<?php

class LeagueTable
{
    public function __construct($players)
    {
        $this->standings = array();
        foreach($players as $index => $p)
        {
            $this->standings[$p] = array
            (
                'index' => $index,
                'games_played' => 0, 
                'score' => 0
            );
        }
    }

    public function recordResult($player, $score)
    {
        $this->standings[$player]['games_played']++;
        $this->standings[$player]['score'] += $score;
    }

    public function playerRank($rank)
    {
        // I'm not sure what to do in here, not even sure where to place the conditional statements
        // but here's me trying to figure it out which I'm 90% sure I'm doing it wrong, 
        // since I'm using too many foreach function and arrays. Most probably not even close
        // to the correct answer.

        $comparison = $result = $this->standings;
        $player_names = array();

        foreach($this->standings as $name => $records)
        {
            foreach($comparison as $name_compare => $records_compare)
            {     
                if($this->standings[$name]['score'] > $comparison[$name_compare]['score'])
                {
                    $result[$name]['index'] = $this->standings[$name]['index'];
                }
                else if($this->standings[$name]['score'] == $comparison[$name_compare]['score']
                      && $this->standings[$name]['games_played'] < $comparison[$name_compare]['games_played'])
                {
                    $result[$name]['index'] = $this->standings[$name]['index'];
                }
                else if($this->standings[$name]['score'] == $comparison[$name_compare]['score']
                        && $this->standings[$name]['games_played'] == $comparison[$name_compare]['games_played'])
                {
                    $result[$name]['index'] = $this->standings[$name]['index'];
                }

                // This is where I'm confused, although there are conditional statemens there
                // but the code inside each "if" and "else if" is the same.

            }
        }

        foreach($result as $name => $records)
        {
            array_push($player_names,$name);
        }

        return $player_names[$rank-1]; //This should return "Chris" based on the record result, but it's not
    }
}

$table = new LeagueTable(array('Mike', 'Chris', 'Arnold'));
$table->recordResult('Mike', 2);
$table->recordResult('Mike', 6);
$table->recordResult('Arnold', 5);
$table->recordResult('Chris', 5);
echo $table->playerRank(1);

谁能帮我解决这个问题？

Answer 1

在你的情况下使用 usort

usort($this->standings, function($a, $b) {
  // Compare scores
  $r = $b['score'] - $a['score'];
  // If two players are tied on score, 
  // then the player who has played the fewest games is ranked higher
  if(! $r) {
    $r = $a['games_played'] - $b['games_played'];
  }
  // If two players are tied on score and number of games played, 
  // then the player who was first in the list of players is ranked higher
  if(! $r) {
    $r = $a['index'] - $b['index'];
  }
  return $r;        
});

// You can watch result of sorting
print_r($this->standings);

Answer 2

您可以在下面找到完整的答案

<?php
class LeagueTable
{
    public function __construct($players)
    {
        $this->standings = array();
        foreach($players as $index => $p)
        {
            $this->standings[$p] = array
            (
                'index' => $index,
                'games_played' => 0, 
                'score' => 0,
                'rank' => $index
            );
        }
    }

    public function recordResult($player, $score)
    {
        $this->standings[$player]['games_played']++;
        $this->standings[$player]['score'] += $score;
    }

    function swap(&$x,&$y) {
        $tmp=$x;
        $x=$y;
        $y=$tmp;
    }  

    public function reRank()
    {
       //ranking all according to score
        foreach($this->standings as $player => $records) {

          foreach($this->standings as $player1 => $records1) {

            if (($records['score'] > $records1['score']) && ($records['rank'] >= $records1['rank']))
            {
                $this->swap($this->standings[$player]['rank'],$this->standings[$player1]['rank']);
            }

            // according to game played
            if (($records['score'] == $records1['score']) && ($records['games_played'] > $records1['games_played']))
            {
                $this->swap($this->standings[$player]['rank'],$this->standings[$player1]['rank']);
            }

            // according to index
            if (($records['score'] == $records1['score']) && ($records['games_played'] == $records1['games_played'])&&
            ($records['index'] > $records1['index']))
            {
                $this->swap($this->standings[$player]['rank'],$this->standings[$player1]['rank']);
            }
          }
       }
    }

    public function playerRank($rank)
    {
        $this->reRank();
        foreach($this->standings as $player => $records)
        {
            if ($records['rank']==$rank-1)
            return $player;
        }
    }
}

$table = new LeagueTable(array('Chris', 'Mike', 'Arnold'));
$table->recordResult('Mike', 2);
$table->recordResult('Mike', 3);
$table->recordResult('Arnold', 5);
$table->recordResult('Chris', 5);

echo $table->playerRank(1);
?>

Answer 3

请尝试以下代码。它会起作用的。

<?php
class LeagueTable
{
    public function __construct($players)
    {
        $this->standings = array();
        foreach($players as $index => $p)
        {
            $this->standings[$p] = array
            (
                'index' => $index,
                'games_played' => 0, 
                'score' => 0,
                'name' => $p
            );
        }
    }

    public function recordResult($player, $score)
    {
        $this->standings[$player]['games_played']++;
        $this->standings[$player]['score'] += $score;
    }

    public function playerRank($rank)
    {

        $comparison = $result = $this->standings;
        $player_names = array();
       
       usort($this->standings, "comparatorFunc");
       

        foreach($this->standings as $name => $records)
        {
            array_push($player_names,$records['name']);
        }
        // echo "hello<br>";
        // print_r($player_names);
        return $player_names[$rank-1]; 
    }
}


function comparatorFunc($a, $b) {
    # Compare scores
    $r = $b['score'] - $a['score'];
    # If two players are tied on score, 
    # then the player who has played the fewest games is ranked higher
    if(! $r) {
        $r = $a['games_played'] - $b['games_played'];
    }
    # If two players are tied on score and number of games played, 
    # then the player who was first in the list of players is ranked higher
    if(! $r) {
        $r = $a['index'] - $b['index'];
    }
    return $r;        
}
    
$table = new LeagueTable(array('Mike', 'Chris', 'Arnold'));
$table->recordResult('Mike', 2);
$table->recordResult('Mike', 6);
$table->recordResult('Arnold', 2);
$table->recordResult('Arnold', 3);
$table->recordResult('Chris', 5);
echo $table->playerRank(1);

Answer 4

<?php
class LeagueTable
{
  public function __construct(array $players)
  {
     $this->standings = [];
     foreach ($players as $index => $p) {
        $this->standings[$p] = [
            'index'        => $index,
            'games_played' => 0,
            'score'        => 0
        ];
      }
   }

    public function recordResult(string $player, int $score): void
    {
       $this->standings[$player]['games_played']++;
       $this->standings[$player]['score'] += $score;
    }

    public function playerRank(int $rank): string
    {
       $result = '';
      /**
       * sort array
       */
       uasort($this->standings, function ($player, $other_player) {
            $r = $other_player['score'] - $player['score'];
            if (!$r) {
                 $r = $player['games_played'] - 
                         $other_player['games_played'];
            }
            if (!$r) {
                $r = $player['index'] - $other_player['index'];
            }
           return $r;
         });
         if ($rank > count($this->standings)) {
              $rank = count($this->standings);
         }
         $index = 1;
         foreach ($this->standings as $player => $player_result) {
           if ($index == $rank) {
               $result = $player;
               break;
            } else {
               $index++;
               continue;
           }
         }
        return $result;
       }
 }

      $table = new LeagueTable(array('Mike', 'Chris', 'Arnold', 'Ali', 
                              'Ahmad'));
     $table->recordResult('Mike', 2);
     $table->recordResult('Mike', 3);
     $table->recordResult('Arnold', 5);
     $table->recordResult('Chris', 5);
     $table->recordResult('Ali', 6);
     $table->recordResult('Ahmad', 3);
     $table->recordResult('Ahmad', 3);
     echo $table->playerRank(1);