1. <?php
    2. /**
    3.  * https://leetcode-cn.com/problems/kth-largest-element-in-an-array
    4.  * @param $nums
    5.  * @param $k
    6.  * @return mixed
    7.  */
    8. /**
    9.  * 小顶堆
    10.  * @param $nums
    11.  * @param $k
    12.  * @return mixed
    13.  */
    14. function topk($nums,$k){
    15.     $h = new SplMinHeap();
    16.     foreach ($nums as $num){
    17.         $h->insert($num);
    18.         if ($h->count() > $k){
    19.             $h->extract();
    20.         }
    21.     }
    22.     // 1、topk的值 $h->top();
    23. //    $te = [];
    24. //    while ($h->valid()) {
    25. //        $cur = $h->current();
    26. //        $te[] = $cur;
    27. //        $h->next();
    28. //    }
    29.     // 2、$te 小顶堆里面的数据数据打印出来即可 $te
    30.     return $h->top();
    31. }
    33. $nums = [2,31,3,4,5];
    34. $k = 3;
    36. //print_r(topk($nums,$k));
    39. function topk2($nums,$k){
    40.     $heap = new SplMaxHeap();
    41.     foreach ($nums as $num){
    42.         $heap->insert($num);
    43.         if ($heap->count() > $k){
    44.             $heap->extract();
    45.         }
    47.     }
    48.     $te = [];
    49.     while ($heap->valid()) {
    50.         $cur = $heap->current();
    51.         $te[] = $cur;
    52.         $heap->next();
    53.     }
    54.     return $heap->top();
    55. }
    56. //function max($numbers,$k){
    57. //    $c = new SplMaxHeap();
    58. //    foreach($numbers as $number){
    59. //        $c->insert($number);
    60. //        if($c->count() > $k){
    61. //            $c->extract();
    62. //        }
    63. //    }
    64. //    $res = [];
    65. //    if ($c->valid()){
    66. //        $res[] = $c->current();
    67. //        $c->next();
    68. //    }
    69. //    return $c->top;
    70. //}
    71. print_r(topk2($nums,$k));

    https://leetcode-cn.com/problems/kth-largest-element-in-an-array