php面試題--並列排名問題

　　給定一個二維數組:

　　　　

<?php
    $data = [
                ['name' =>'j1', 'score' => '80'],
                ['name' =>'j2', 'score' => '90'],
                ['name' =>'j3', 'score' => '50'],
                ['name' =>'j4', 'score' => '70'],
                ['name' =>'j5', 'score' => '95'],
                ['name' =>'j6', 'score' => '100'],
                ['name' =>'j7', 'score' => '60'],
                ['name' =>'j8', 'score' => '50'],
　　　　　　　　　 ['name' =>'j9', 'score' => '80'],
                
    ];
?>

最後的結果爲:

[
    ['name' => 'j6', 'score' => '100', 'deep' => 1],
    ['name' => 'j5', 'score' => '95', 'deep' => 2],
    ['name' => 'j2', 'score' => '90', 'deep' => 3],
    ['name' => 'j1', 'score' => '80', 'deep' => 4],
    ['name' => 'j9', 'score' => '80', 'deep' => 4],
    ['name' => 'j4', 'score' => '70', 'deep' => 5],
    ['name' => 'j7', 'score' => '60', 'deep' => 6],
    ['name' => 'j3', 'score' => '50', 'deep' => 7],
    ['name' => 'j8', 'score' => '50', 'deep' => 7]
]

要求全部關於排序的操做都不能使用php自帶的系統函數，必須本身寫排序算法（冒泡、插入、選擇、快排.....）,時間20分鐘

 

2018年都過了27天了，總結下本身2017年的面試經歷吧。這是上次面試遇到的編程問題，與你們分享本身的處理方法:

先排序用的是選擇排序（其實面試那天用的是冒泡算法，當時作完無法拷貝，如今是我第一家公司作的某個項目寫的，最後程序可能結果不對，可是個人思路就是先排序在排名，人比較懶，也不想再去寫那個冒泡了，實際開發中我都是用的是php自帶的系統函數處理的有一個很牛逼的排序函數uasort()，還支持callback，案列地址：http://www.jb51.net/article/71654.htm）

        for($i=0;$i<count($barr)-1;$i++){
                $minIndex = $i;   //本身假定是最大的
                for($j=$i+1;$j<count($barr);$j++){
                    if($barr[$minIndex]['num'] < $barr[$j]['num']){//若是這個值比最大的還大
                       $minIndex = $j;                       
                    }
                }
                if($minIndex != $i){
                    $temp = $barr[$minIndex];
                    $barr[$minIndex] = $barr[$i];
                    $barr[$i] = $temp;                
                }
                
        }

 排名：原理就是循環數組，追加deep值，因爲是按照從高到低的順序排列的，那麼第一個就是第一名，當相鄰兩個數字同樣deep就不加不然就加+1

$p = 1;
foreach ($barr as $k => $v) {
               if ($k==0) {
                    $barr[$k]'deep'] = 1;
                } else {
                     if($barr[$k-1]['score']==$arr[$k]['score'])
                          $barr[$k]['deep']=$p;
                }else{
                          $barr[$k]['deep']=++$p;
                }
}