PHP Common sort and find algorithm, PHP sort algorithm _php Tutorial

PHP Common sort and find algorithm, PHP sorting algorithm

This paper summarizes the common PHP sorting algorithm and lookup, in the design of the algorithm has a good reference value. We are now sharing it for your reference. Specific as follows:

<?php/** * PHP most commonly used four sorting methods and two search methods * The following sorting methods all pass the test * auther:soulence * DATE:2015/06/20 *///php Bubble Sort method function Bubbleso RT (& $arr) {//This is an intermediate variable $temp = 0;//We want to sort the array, from small to large//outer loop $flag =false;//This optimization will be very efficient, generally enough for ($i =0; $i
 
  $arr [$j +1]) {$temp = $arr [$j];        $arr [$j]= $arr [$j +1];        $arr [$j +1]= $temp;     $flag =true;   }} if (! $flag) {//is already ordered break;  } $flag =false;  }}//php Select Sort method efficiency is higher than bubbling function Selectsort (& $arr) {$temp = 0; for ($i =0; $i
  
   $arr [$j]) {$minVal = $arr [$j];      $minIndex = $j;    }}//Last Exchange $temp = $arr [$i];    $arr [$i]= $arr [$minIndex];  $arr [$minIndex]= $temp; }}//Insert Sort method (small to large sort) the efficiency is higher than the sorting method. Function Insertsort (& $arr) {////default subscript 0 is already ordered for ($i =1; $i
   
    
= 0 && $insertVal < $arr [$inserIndex]) {//shift the number back $arr [$inserIndex +1] = $arr [$inserIndex];    $inserIndex--;  }//Insert (at this point to find the appropriate location for $inserindex) $arr [$inserIndex +1] = $insertVal;   }}//Quick Sort method The first is not the function quickSort ($left, $right,& $arr) {$l = $left;   $r = $right;   $pivot = $arr [($left + $right)/2];     while ($l < $r) {while ($arr [$l]< $pivot) {$l + +;     } while ($arr [$r]> $pivot) {$r--;     } if ($l >= $r) {break;     } $temp = $arr [$l];     $arr [$l]= $arr [$r];     $arr [$r]= $temp;     if ($arr [$l]== $pivot) {--$r;     if ($arr [$r]== $pivot) {+ + $l;    }} if ($l = = $r) {$l + +;   $r--;   } if ($left < $r) QuickSort ($left, $r, $arr); if ($right > $l) quickSort ($l, $right, $arr);}  /** * Quick Sort method Implementation of the second method of implementation of the * PHP Quick Sort method * $order ASC Small to large desc large to small default is ASC * $order value can only be ASC desc If you write a value is also sorted by ASC */function  QuickSort2 ($arr, $order = ' asc ') {if (count ($arr) <= 1) return $arr;  $arr _left = $arr _right = Array ();$val = $arr [0];unset ($arr [0]);   foreach ($arr as $v) {if (Strtolower ($order) = = ' desc ') {if ($v < $val) $arr _right[] = $v;  else $arr _left[] = $v;   }else{if ($v > $val) $arr _right[] = $v;  else $arr _left[] = $v; }} $arr _left = QuickSort ($arr _left, $order);  $arr _right = QuickSort ($arr _right, $order);  Return Array_merge ($arr _left,array ($val), $arr _right);}  Here is the lookup $arr=array (46,90,900,0,-1);//This is a sequential query for function search (& $arr, $findVal) {$flag =false; for ($i =0; $i
    
     < $leftindex条件成立，说明没有这个数，则退出="" if($rightindex="" $leftindex){="" "找不到该数";="" return;="" 首先找到中间这个数="" round是出于如果出现小数，四舍五入="" $middleindex="round(($rightIndex+$leftIndex)/2);" 如果大于则向后面找="">$arr [$middleIndex]) {BinarySearch ($arr, $findVal, $middleIndex +1, $rightIndex);  If it is less than the middle number, look to the front}else if ($findVal < $arr [$middleIndex]) {BinarySearch ($arr, $findVal, $leftIndex, $middleIndex-1); }else{echo "Find this number.  Subscript is $middleindex "; }}?>
    
   
  
 

It is hoped that the sorting algorithm and the example of finding algorithm in this paper will help the PHP program design.

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